21.2: Factors Affecting Skin Integrity
By the end of this section, you will be able to:
- Identify risk factors for impaired skin integrity
- Examine common skin disorders that cause impaired skin integrity
- Describe health promotion behaviors related to skin integrity
Skin integrity refers to the overall health of the skin. Factors that influence healthy skin are patient specific. These factors include age, genetics, and overall health. For example, the skin color of a patient of Asian descent will appear different from that of a Caucasian person. In addition, skin changes as people age, so the nurse must consider age when assessing a patient’s skin. It is crucial that nurses obtain the patient’s health history and perform an assessment to identify risk factors for impaired skin integrity to effectively implement nursing interventions and provide education to patients and families. The nurse must be aware of common skin disorders that can lead to impaired skin integrity as well as health promotion behaviors related to skin integrity.
Risk Factors for Impaired Skin Integrity
When the skin is healthy and unbroken, the skin is able to efficiently carry out its functions. Resistance of the skin and mucous membranes to injury varies among patients and is dependent on factors including age and medical conditions. Patients with adequate nutrition are also more resistant to injury or disease. Adequate perfusion is vital in maintaining cell life. When skin integrity is impaired, cells do not get the nourishment they need and cannot eliminate wastes effectively. To identify risks for impaired skin integrity, the nurse must examine lifestyle and behavioral factors as well as genetic and state of health factors.
Lifestyle and Behavioral Factors
Lifestyle and behavioral factors that affect skin integrity include a patient’s nutrition, activity levels, sexuality, medications used, illicit drug use, body piercings, tattoos, and substances that come in contact with the skin like soaps, detergents, and lotions. Nutrition plays an important role in the health of a patient’s skin. Inadequate nutrition may lead to skin breakdown, delayed wound healing , premature aging of the skin, inflammation, dryness, and changes in hair. A patient’s exposure to the sun or other UV light may place them at risk of skin cancer as a result of prolonged exposure. A patient’s activity levels may also place them at risk of other injuries (e.g., abrasions, burns, bruising) depending on the type of activity. For example, hikers may fall and be prone to abrasions or bruising.
Patients who engage in risky sexual behavior (e.g., having unprotected sex, having multiple partners) are at a higher risk of contracting sexually transmitted infections. Human immunodeficiency virus (HIV), acquired immunodeficiency syndrome, and hepatitis C are three common sexually transmitted infections. People with hepatitis C may experience discoloration or jaundice (yellowing of skin and mucus membranes), swelling, itching, and hives. People who inject illicit IV drugs or share needles with other people also are at risk of these and other infections. They may also develop Kaposi sarcoma , which is a rare type of cancer caused by a virus. It may appear as a red or blue patch, similar to a bruise, and is often found on the skin or inside the mouth. Body piercings or tattoos may place patients at risk of bacterial or viral infections, deformities, scarring, and nerve damage (van der Bent et al., 2021).
The use of certain types of hygiene products may also place a patient at risk of impaired skin integrity . Certain types of soaps, lotions, and detergents may be too harsh for a person’s skin based on their age, health condition, and genetics. Some detergents and soaps increase the pH levels of the stratum corneum , and those products may cause rashes, inflammation, dermatitis, and acne breakouts. Older people who do not use an emollient (an ingredient that soothes dryness) are at risk of impaired skin integrity because their skin is dry and more susceptible to cracking. Patients who work with chemicals are also at risk of impaired skin integrity and should use appropriate personal protective equipment when working with those substances. Lotions with sunscreen protection factor (SPF) should be used and protective clothing worn when spending time in the sun. Not taking these precautions increases the risk of sunburns, premature aging of the skin, wrinkles, and skin discoloration.
State of Health and Genetic Factors
State of health and genetic factors may affect the skin. Nutrition can adversely or positively affect the health of the skin. Some people experience dehydration and malnourishment caused by an illness versus a lifestyle choice. Dehydration and malnourishment result in a deficiency in fluids, protein, and vitamin C. This causes the skin to lose its elasticity and become more susceptible to breakdown.
Patients with impaired sensation (e.g., paralysis, poor circulation, nerve damage) are at risk of impaired skin integrity caused by the inability to sense pressure, friction, pain, or extreme temperatures. For example, a patient with diabetic neuropathy may not be able to feel the ice pack on their foot after surgery. If the patient were to forget it was there, they could experience frostbite or other skin injury because of the inability to feel any damage being caused. Patients who have diabetes are prone to skin problems caused by alterations in vascular, immune, neuropathic, and biochemical components. These components impair tissue oxygenation and decrease uptake of essential nutrients needed to maintain skin integrity. People with diabetes may also experience delayed wound healing , lesions that turn into ulcers and become necrotic, and recurrent infections.
Side effects of certain medications may also affect skin. For example, localized pruritus (or itching) is common with hydrocodone , and patients may scratch themselves in an attempt to relieve the itching. Corticosteroids cause thinning of the skin, making it more susceptible to injury, and certain antibiotics increase sensitivity to sunlight causing an individual to burn easily. Patients who experience incontinence or have issues with diarrhea are at risk of skin breakdown as a result of the excess moisture. Patients with jaundice are at risk of lesions and infections from scratching because of dry, itchy skin. There are also numerous conditions that cause secondary disruptions to the integumentary system . For example, patients undergoing radiation treatment for cancer are at risk of erythema (a reddening of the skin), pruritus, or loss of skin integrity (Figure 21.8).
Numerous skin conditions may have a genetic component and may be inherited (e.g., vitiligo , acne, melanoma, psoriasis , eczema ). Vitiligo has a polygenic inheritance pattern, meaning that multiple alleles contribute to the genetic component of the disease. Fifteen acne-related genetic variants may influence the shape of hair follicles, which may make them more susceptible to bacterial inflammation. Melanoma has been known to occur in several members of the same family. These familial cases may be caused by inheriting several genes associated with melanoma that increase the risk of developing melanoma. Psoriasis and eczema have a genetic predisposition component and often cause skin lesions. They also may be caused by inflammation resulting from eating certain products (e.g., gluten, dairy).
Common Skin Disorders
There are various skin disorder s that the nurse should be aware of to effectively care for their patients. Common skin disorder classifications include bacterial infections, viral infections, fungal infections, inflammatory reactions, and skin cancer s. It is crucial for the nurse to be able to identify and describe skin disorders as well as their underlying causes and treatments.
Bacterial Infections
Bacteria naturally reside on the skin. An infection can occur, however, when the skin is not intact, allowing bacteria to enter through hair follicles or breaks in the skin (e.g., scrapes, surgical incisions, bites). Some bacterial infections are localized and involve just the skin, the soft tissues under the skin, or they can become systemic involving multiple body systems. Common bacterial infections of the skin include impetigo, folliculitis , carbuncles, and cellulitis (Table 21.1).
| Disorder | Description | Example |
|---|---|---|
| Impetigo | Contagious superficial skin infection | |
| Folliculitis | Infection of the hair follicle | |
| Carbuncle | Clusters of deep skin abscesses | |
| Cellulitis | Localized infection and inflammation |
Impetigo
Most commonly found in children, impetigo is a highly contagious superficial skin infection. Patients with impetigo can spread it to other areas of their own body as well as to other people they come in contact with. Although it can occur anywhere on the body, it primarily occurs on the arms, legs, and face. Impetigo is either bullous or nonbullous in nature. Usually sporadic, bullous impetigo develops on intact skin and is caused by Staphylococcus aureus . Flaccid bullae generally grow in size to form larger blisters filled with clear yellow to dark turbid fluid and burst to expose raw skin that becomes covered with a thin brown crust. The most common kind of impetigo is nonbullous impetigo that usually occurs after injury to the skin or as a secondary bacterial infection of another skin disorder like atopic dermatitis. Nonbullous impetigo presents as clusters of pustules that rapidly break down and form thick, adherent, honey-colored crusts on the face and extremities. Other risk factors for impetigo include poor hygiene and a moist environment. Treatment for impetigo may include topical or oral antibiotics .
Often called deep impetigo, ecthyma is a skin infection that occurs deep inside the skin characterized by shallow, small ulcers that look punched-out and may contain pus. The brown crust that covers the ulcers is thicker than the crust that covers the ulcers of impetigo. Treatment options for impetigo and ecthyma include antibiotic ointments or creams for smaller areas. Larger infected areas or areas that are not responding to the topical antibiotics may require oral antibiotics. The infected areas should be washed gently with soap and water multiple times a day to remove crusts. Individuals who have recurrent infections should have a nasal swab cultured to see if they are a nasal carrier of Staphylococcus or Streptococcus . People who are nasal carriers will need a topical antibiotic applied to their nasal passages (Rehmus, 2023).
Folliculitis
An infection of the hair follicle that often results from occluded hair follicles is termed folliculitis . It may affect a single hair follicle or multiple hair follicles. Common risk factors for folliculitis include poor hygiene, maceration (occurs when skin is exposed to a moist environment for too long), occlusive emollient products, and contact with contaminated water. Folliculitis often appears as pustules surrounded by erythema where a hair follicle is present. Hair follicles may easily fall out as well. Treatment includes warm compresses after washing with antibacterial soap and water multiple times a day, topical antibiotics, and oral antibiotics.
Carbuncle
A carbuncle is a skin abscess that connects with other carbuncles below the surface of the skin to form clusters, often forming when one or more hair follicles become infected. If left untreated, the abscesses fill with pus and will rupture, discharging a creamy pink or white fluid. If the abscess is too deep, it may not be able to drain on its own. Bacteria can spread from the abscess and infect surrounding tissues and lymph nodes. Infected individuals may also have a fever, chills, and malaise. Carbuncles are likely to leave a scar. Most carbuncles are caused by Staphylococcus aureus . Risk factors for the development of carbuncles include poor overall health, friction from shaving or clothing, and poor hygiene. Patients with weakened immune systems are more likely to develop Staphylococcus infections that lead to carbuncles. Some skin abscesses may go away on their own with the use of warm compresses. However, some carbuncles may require a provider to open and drain the abscess and then wash out the pocket with a sterile saline solution. Oral antibiotics may also be needed to aid in treating the infection. Individuals with recurrent skin abscesses may be instructed to wash their skin with antiseptic solutions (e.g., iodine) (Rehmus, 2023).
Cellulitis
A localized infection and inflammation of the skin and tissues beneath the skin is called cellulitis . It is most often caused by Streptococcus , Staphylococcus , and Methicillin-resistant Staphylococcus aureus. The infection usually occurs when the bacteria enters open wounds, skin abscesses, fungal infections, or other skin conditions. Although cellulitis can occur anywhere on the body, it occurs most often on the legs and affects one side of the body. Bilateral cellulitis is rare, and its presence should warrant assessment of other health conditions (Chuang et al., 2022).
The infection generally presents with redness, tenderness, and pain. The skin also often becomes hot and swollen and may look slightly pitted. A fluid-filled vesicle (small blister) or a bulla (large blister) may appear on the infected areas. Some patients may experience fever, rapid heart rate, headache, confusion, hypotension, or chills. If the infection spreads to the lymph nodes, the nodes can become tender and swollen, and the vessels can become inflamed. Treatment may include antibiotics, drainage of any abscesses, and treatment of any disorders contributing to the infection (Rehmus, 2023). Compression stockings (thromboembolic deterrent [TED] hose) may also be effective by reducing edema (swelling caused by excessive buildup of fluid in tissue spaces or a body cavity) and increasing blood flow.
Information regarding the therapeutic benefits of compression stockings is presented by Wound Care Centers. Compression stockings help reduce edema and increase blood flow back to the heart.
Viral Infections
Viral skin infections are the result of a reaction from a systemic virus within the body or an infection of the skin itself. This type of infection encompasses a variety of conditions such as herpes simplex, herpes zoster , verruca , and human papillomavirus (Table 21.2). Viral skin infections are often contagious, and some may be passed by skin-to-skin contact or through the air when the infected individual coughs or sneezes.
| Disorder | Description | Example |
|---|---|---|
| Herpes simplex | Infection caused by herpes simplex virus type 1 (HSV-1) and HSV-2 | |
| Shingles | Rash associated with varicella-zoster virus | |
| Verruca | Growths on the skin caused by human papillomavirus |
Herpes Simplex
A viral infection that can cause painful blisters or ulcers is herpes simplex and is categorized into herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). Most often, HSV-1 spreads by oral contact and causes infections in or around the mouth or lips. This virus presents as ulcers or blisters (cold sores). It can also cause genital herpes if an infected person made contact with another person’s genital mucosa. HSV-1 is commonly spread through kissing, sharing objects that are in or near the mouth, and any other skin-to-skin contact. On the other hand, HSV-2 is spread by sexual contact and causes genital herpes. This virus usually presents as open sores, blisters, or bumps around the anus or genitals. It may also appear in the sacral area. Someone who has an active outbreak and is giving birth can also pass the virus to the baby.
It is not uncommon for patients with herpes infections to have little to no symptoms; therefore, an infected individual may unknowingly spread the virus. The first outbreak may be accompanied by body aches, swollen lymph nodes, and fever. Subsequent outbreaks may begin with burning, itching, or tingling prior to the appearance of blisters. The blisters often appear in clusters and break open, ooze, and crust over. Outbreaks can be caused by triggers like stress, fever, illness, surgery, menstrual periods, and sun exposure . This virus can be recurring and is not curable. Antiviral medications (e.g., valacyclovir [Valtrex] and acyclovir [Zovirax]) may be used to shorten the length and severity of the herpes simplex breakout. Some patients may take the medications daily to prevent outbreaks and lessen the chance of spreading it to others. Other treatment options include minimizing triggers, topical anesthetics, topical ointments, or over-the-counter pain medications like acetaminophen (Tylenol) or ibuprofen (Motrin). Patients with genital herpes may decrease symptoms by wearing loose clothing and sitting in a warm bath without soap. Cold drinks or popsicles may also aid in providing relief to those with oral cold sores. Patients should also be educated on the importance of informing any potential sexual partners and abstaining from sexual activity when lesions are present, replacing toothbrushes or lip balms used during the presence of a cold sore, and not sharing utensils or drinks with uninfected people (World Health Organization, 2023).
Herpes Zoster
The varicella (chickenpox) infection is caused by the varicella-zoster virus. After the initial illness has ended, the virus remains dormant in the dorsal root ganglia and can reactivate later in the person’s life causing a painful, maculopapular rash called herpes zoster (shingles). Patients who have received a varicella vaccine are also at risk of developing herpes zoster later. The rash associated with shingles most often appears on the trunk of the body along a thoracic dermatome. The rash primarily stays on one side of the body, follows dermatomes, and does not cross the midline. Although not common, the rash can affect three or more dermatomes and is called disseminated zoster . This type of rash occurs in patients with a weakened or suppressed immune system. The symptoms are often painful, tingly, or itchy and may precede the appearance of the rash. Some patients may also experience headache, malaise (overall weakness) in the prodromal state (period between the appearance of initial symptoms and the full development of an illness), chills, or photophobia (bright light sensitivity). Vesicles develop into clusters, which continue to form over three to five days and gradually dry and crust over. The rash usually heals in two to four weeks and can leave scarring or pigmentation changes behind. Shingles can be prevented by the recombinant zoster vaccine. This virus can spread to others when it is active and can cause varicella in those who have never had varicella or been vaccinated against it. Antiviral medications, like valacyclovir and acyclovir, may also be used to shorten the length and severity of a shingles breakout (Centers for Disease Control and Prevention, n.d.).
Verruca
A growth on the skin caused by the viral infection human papillomavirus (HPV) is called a verruca or a wart. The warts may appear raised or flat and can have a black dot in the middle. Warts are often not painful, although some people may complain of pain. Warts may develop at any age but are more commonly found in children. Patients with warts may have as few as one or as many as hundreds. Warts are contagious and can spread from one area of the patient’s body to another body part or to another person through prolonged or repeated contact. Only a small break in the skin needs to be present for the virus to spread (Dinulos, 2023c). Genital warts, however, are spread by sexual contact.
Verrucae are classified by their shape and location. A warts that grows in clusters is referred to as a mosaic wart . Common warts are firm, round, or irregularly shaped growths with a rough surface. They may be brown, yellow, gray-black, or light gray and are generally less than 1 centimeter across. These warts appear on the face, fingers, elbows, and knees. A wart on the soles of the feet is a plantar wart and is usually flat due to the pressure of standing and walking. Warts that appear on the soles of the feet may cause pain when walking or standing. A wart found on the palms of the hand is a palmar wart . Both palmar and plantar warts tend to be hard and flat with well-defined boundaries and a rough surface. Thick, cauliflower-like growths around the fingers are known as periungual warts. A long, small, narrow growth that appears on the lips, face, or eyelids is a filiform wart . A warts that may appear in areas that are shaved or along stretch marks is a flat wart . They are typically smooth, flat topped, and either yellow-brown, pink, or flesh colored.  This type of wart can be flat, smooth, and irregular or velvety bumpy growths with a cauliflower-like texture (Dinulos, 2023c).
Generally, warts are easily recognizable by appearance. Occasionally, a biopsy may be needed to confirm the diagnosis. Treatment options include applying topical chemicals and burning, cutting, or freezing the wart. A candidal yeast antigen may be injected into the warts causing an immune response to fight against the virus (Dinulos, 2023c). Warts may return even after removal. The human papillomavirus (HPV) vaccine may be used to prevent the spread of the virus. Patients with genital warts should have the warts removed to prevent spreading from person to person. They should also be educated on safe sex and the need to inform their partners of the diagnosis.
Fungal Infections
Fungal skin infections caused by fungus overgrowth most commonly occur in moist areas of the skin like between the toes, under breasts, or in the genital areas. Fungal skin infections are usually caused by yeasts (e.g., Candida albicans ) or dermatophytes (e.g., Microsporum) . The fungi live on the stratum corneum and typically do not penetrate deeper into the skin. Patients with a higher weight are more likely to have fungal skin infection s related to excessive skinfolds. Patients with diabetes are also at risk of fungal infections (Aaron, 2023). Common fungal skin infections include six types of tinea (Table 21.3).
| Disorder | Description | Example |
|---|---|---|
| Tinea pedis | Also known as athlete’s foot; fungal infection characterized by a buildup of scale and may be accompanied by redness and itching | |
| Tinea barbae | Also known as beard ringworm; generally a superficial infection but may occur deeper | |
| Tinea corporis | Also known as body ringworm; a fungal skin infection affecting the face, arms, trunk, and legs | |
| Tinea cruris | Also known as jock itch; a fungal skin infection of the groin | |
| Tinea capitis | Also known as scalp ringworm; a fungal infection of the scalp | |
| Tinea unguium | Also known as onychomycosis; a fungal infection of the toenail or fingernail |
Tinea
Also known as ringworm, tinea may be found on the feet, beard, body, groin, scalp, or toes. The condition tinea pedis (or athlete’s foot) is characterized by a buildup of scale and may be accompanied by redness and itching. This infection is commonly caused by sweat from the feet accumulating between the toes allowing fungi to grow. This infection can spread to others who share showers, bathrooms, or other areas where infected individuals walk barefoot. Patients who wear tight shoes are also at risk of developing this infection. Fluid-filled blisters may also form with this infection. If the scaling is severe, the skin may crack and can lead to bacterial infections. Athlete’s foot may be treated by topical antifungal ointments or oral antifungals like itraconazole (Sporanox). Prevention measures include wearing sandals or shower shoes in communal bathrooms, wearing breathable shoes, frequently changing socks, minimizing moisture on feet and in footwear, and completely drying feet and in between toes after bathing. Antifungal powders may also be used to aid in keeping the feet dry (Aaron, 2023).
A tinea barbae (beard ringworm) infection is generally superficial but may occur deeper into the dermis . Tinea barbae is characterized by circular patches or a swollen patch that may ooze pus and can result in scarring or whisker loss. Most beard skin infections are caused by bacteria rather than fungi; however, tinea barbae is a fungal infection. Antifungal medications or corticosteroids are common treatments for beard ringworm (Aaron, 2023).
The fungal skin infection tinea corporis (body ringworm) affects the face, arms, trunk, and legs. This infection is characterized by round, pink-to-red patches with raised, scaly borders that can be itchy. Clearing in the center may also be present. This infection can spread from one area of an infected person’s body to another or from person-to-person contact. Antifungal medications may be applied topically or taken orally to treat this infection (Aaron, 2023).
A tinea cruris (jock itch) infection is a fungal skin infection of the groin. This is often characterized by a painful, itchy rash with a scaly, pink border. This infection is more common in men and is caused by trapped moisture between the scrotum and thigh and most often develops in warm weather or when wearing tight or wet clothing. Patients of a higher weight are at risk as well because of trapped moisture in skinfolds. The infection usually begins in the skinfolds of the genital area and spreads to the upper inner thighs. Antifungal medications may be taken orally or applied topically (Aaron, 2023).
The fungal infection tinea capitis (scalp ringworm) occurs on the scalp. This infection is characterized by a scaly, dry patch, a patch of hair loss, or both. The hair shafts may break at the surface (black dot ringworm) or break above the surface (gray patch ringworm). This infection can also cause dandruff-like flaking. A kerion may also be present. A kerion is a large, inflamed, swollen and sometimes painful patch that can ooze pus. A culture may be needed to assess the type of fungus, or a UV light may be used to confirm the diagnosis. Treatment of scalp ringworm includes oral antifungals, antifungal creams, selenium sulfide (Selsun Blue) shampoos, or corticosteroids (Aaron, 2023).
The fungal infection tinea unguium involves the toenail or fingernail. This infection is characterized by thickened nails that crumble easily and have white or yellow discoloration. The whole nail may become detached in more severe infections. If left untreated, the patient may have pain, balance issues, or a candidal infection. Treatment options include oral antifungals, topical ciclopirox olamine (Penlac) nail lacquer, and topical antifungals. Prevention is similar to that of preventing athlete’s foot.
Parasitic Infections
A parasite is an organism that lives in or on an organism of a different species (the host) and depends on the host for nutrients. Parasitic skin infections occur when insects or worms burrow into the skin of a patient to lay their eggs or live there. Common parasitic skin infection s include scabies and pediculosis (lice) (Table 21.4). Both infections are spread from person to person through physical contact. The parasites can live on physical objects such as brushes, clothing, furniture, and bedding; therefore, the parasites can spread to another person as well when contact is made with infested objects. Parasitic infections are generally treated by removing the source of the infestation as well as using topical and oral medications to aid in killing the parasites and to relieve any swelling, itching, or skin damage (Campbell & Soman-Faulkner, 2023).
| Disorder | Description | Example |
|---|---|---|
| Scabies | Mites | |
| Pediculosis capitis | Head lice | |
| Pediculosis corporis | Body lice |
Scabies
The Sarcoptes scabiei mite causes scabies . Scabies are accompanied by extreme itching, no matter how few mites have burrowed into the skin. Initially, the burrows are often visible and can be anywhere on the body, except they are less likely on the face. The burrows appear as a thin line and can have a tiny bump where the mite is located. Darker-skinned individuals may only display raised, solid areas. Due to the intense scratching, this infestation can often turn into a bacterial infection. Over time, the areas usually become inflamed, making the burrows less visible. Infestations that turn severe may cause areas of crusted, thickened skin that do not itch. Risk factors for attracting scabies are crowded conditions like schools, multifamily homes, and shelters. Hygiene is not a factor with scabies.
Treatment for scabies includes applying topical permethrin (Acticin) creams or lindane (Lindane) lotions to the skin for several hours before washing off. Lindane lotion is contraindicated in children under the age of 2 years, patients with a seizure disorder, and pregnant or breastfeeding patients. For older children and adult patients, spinosad suspension (Natroba) may be applied to the skin avoiding the eye. Ivermectin (Stromectol) may also be taken orally for people who have not had therapeutic benefits from topical medications or cannot use them. Itching can be relieved by oral and topical antihistamines. Infestations that progress to a bacterial infection may also require antibiotics. Physical objects that have come in contact with an infested patient should be washed in hot water, thoroughly dried on high heat, and stored in a sealed plastic bag for three days. Individuals who have close contact with a patient experiencing an infestation should also be treated (Dinulos, 2023a).
Pediculosis
A lice infestation is pediculosis . Lice are wingless insects that are not easily seen and may infect the body, head, or pubic area. Each type of lice can cause severe itching and bites that range from red (body and head lice) to grayish blue (pubic lice). An infestation with lice may be diagnosed with the presence of lice, nits (or eggs), or both. A fine-tooth comb may be needed to assess the hair for lice, and the nits may be easier to see versus the lice itself. Body lice are often found in the seams of clothing and bedding. Pubic lice may require a UV light or a microscope to be seen. Pubic lice may leave feces on the patient’s skin or underwear, which are characterized by dark brown specks. An infestation with lice will require replacing or thoroughly cleaning and drying linens and clothing. Items that are not able to be laundered can be placed in an airtight bag for two weeks to kill the lice. People who have close contact with an infected patient should also treat themselves, including sexual partners (Dinulos, 2023b).
Body lice ( pediculosis corporis ) live on and lay their eggs on bedding and clothing rather than the skin. The lice will migrate to various areas of the body to feed. Patients who live in crowded areas, have poor hygiene, or are of low socioeconomic status are more at risk of acquiring body lice. The lice spread because of sharing contaminated bedding and clothing. This type of lice can also transmit different types of fevers (Dinulos, 2023b). Treatment includes thoroughly cleaning linens and clothing.
Head lice ( pediculosis capitis ) are found on the hair and scalp. The lice lay eggs that take about one week to hatch and are called nymphs. It takes another seven days for the nymphs to reach their adult stage.  If the lice are deprived of blood, they will usually die within one to two days.  Shampoos that contain permethrin (Acticin), piperonyl butoxide (Red Pediculicide), or lindane (Lindane) are effective for treating head lice. Creams that contain malathion (Ovide) or spinosad (Natroba) suspensions may also be effective. Nits need to be removed with a fine-tooth comb. Treatments must be repeated seven to ten days later to kill any potential newly hatched lice. Ivermectin (Stromectol) may also be used if lice are resistant to medicated shampoos or creams (Dinulos, 2023b).
Pubic lice ( pediculosis pubis ), often referred to as crabs, infest the hairs of the anal and genital areas but can also infest the thigh, chest, and facial hair. This type of lice may be spread by sexual contact or close contact or by physical objects like linens and clothing. The same shampoos and creams used for head lice are effective for treating pubic lice. In addition, petroleum jelly, physostigmine ointment, fluorescein eye drops, petrolatum salve, and oral ivermectin (Stromectol) are effective for the lice that have infested a patient’s eyelashes (Dinulos, 2023b).
Inflammatory Reactions
Inflammatory skin reactions are either chronic or acute and are the result of a hypersensitivity reaction, an autoimmune disorder, or a genetic predisposition. These skin reactions may also recur when the stress factors or environmental triggers that caused the reaction are present. Inflammatory skin reactions include eczema , seborrheic dermatitis , urticaria , acne vulgaris , psoriasis , and systemic lupus erythematosus (SLE) (Table 21.5). These reactions require obtaining a comprehensive health history including family history, medications, diet, hygiene practices, and environmental conditions as well as a full assessment to identify possible triggers or causes.
| Disorder | Description | Example |
|---|---|---|
| Eczema | Itchy, chronic inflammation of the skin | |
| Seborrheic dermatitis | Inflammatory skin reaction primarily on the scalp and face | |
| Urticaria | Rash characterized by wheals and erythema | |
| Acne vulgaris | Inflammatory skin reaction caused by clogged hair follicles | |
| Psoriasis | Recurring, chronic condition that causes red patches with silvery scales | |
| Systemic lupus erythematosus | Chronic, autoimmune inflammatory disorder, often presents with a butterfly rash |
Eczema
The condition eczema (atopic dermatitis) is a part of the atopy family. Atopy means there is a genetic tendency to develop allergic conditions like asthma, eczema, and allergic rhinitis and is associated with a heightened immune response. This rash is characterized by itchy, chronic inflammation of the outer skin layers. In the acute phase, the rash may appear as red, oozing, and crusted areas with occasional blisters present. The chronic phase may have dry, thickened areas caused by scratching and rubbing. The rash may occur in one or more areas in adult patients and can spread to several areas on infants. The rash can vary in intensity, color, and location but is always itchy and triggers scratching, which can cause the skin to break and bleed. Stress, irritation, and dry air also make the itching more intense. Environmental triggers include harsh soaps, excessive bathing or handwashing, sweating, rough fabrics (e.g., wool), or Staphylococcus aureus present on the skin. Allergens like wheat, dairy, and eggs may also be a trigger. Tears in the skin caused by scratching or rubbing can often lead to bacterial infections.
Prevention includes minimizing triggers and managing stress. Treatments include skin care, UV light, corticosteroids, and biologic agents. General skin hygiene includes using soap substitutes, applying moisturizers after bathing, using lukewarm water, and patting skin dry. Antihistamines may also be used to relieve itching. Antibiotics may be needed when the reactions escalate to bacterial infections or for patients who are at risk of developing an infection (Ruenger, 2023). This reaction can be disabling and have long-term emotional effects that may require additional assessment and interventions to promote positive coping and body image.
Seborrheic Dermatitis
The inflammatory skin reaction seborrheic dermatitis affects the scalp and may also be present on the face, around the ears, and occasionally on other areas that have oil glands present. This reaction is more common in infants and adult patients from 30 to 70 years of age. Genetic factors and cold-weather conditions affect the severity and risk of this disorder. The rash is characterized by greasy, yellow scales, pruritus , and dandruff.
Seborrheic dermatitis is triggered by yeast, stress, hormonal changes, harsh detergents or soaps, dry or cold weather, certain medical conditions (e.g., HIV, Parkinson disease), and certain medications (e.g., psoralens [Uvadex] and lithium [Lithobid]). Patients with darker skin may have a darker-colored rash and have lesions around the hairline with possible skin discoloration. Treatments include application of antifungal creams (efinaconazole [Jublia]); corticosteroid creams or solutions (clocortolone pivalate [Cloderm]); calcineurin inhibitors (tacrolimus [Prograf]); antifungal shampoos; and shampoos containing zinc pyrithione (DermaZinc), selenium sulfide (Selsun Blue), and salicylic acid (Baker P&S). Treatment for infants differs by washing with a mild shampoo and applying hydrocortisone cream or fluocinolone oil on the face or into the scalp. Antifungal creams may also be used. Treatment for young children includes using mineral oil, corticosteroid gel, or olive oil to the affected areas (Ruenger, 2023). Treatment often requires repeating until the seborrheic dermatitis is resolved and can be restarted if it returns.
Urticaria
The type I hypersensitivity reaction urticaria (or hives) results from an immunologically mediated antigen-antibody response of mast cells releasing histamine. This reaction is characterized by wheals (or hives) and erythema present after vasodilation and increased vascular permeability. The rash is easily identifiable by a raised, swollen, flesh-colored or red bumps or welts on the skin. This reaction often begins rapidly and may be accompanied by swelling of the face, lips, throat, or airways ( angioedema ). The wheals can take several weeks to resolve.
The most common triggers include medications, foods, infections, stress, insect bites, and environmental stimuli (e.g., sun, light clothing, sun, heat, cold). Any of the triggers can cause a reaction if injected, inhaled, consumed, or touched. Autoimmune conditions can also trigger urticaria. Any potential or identified trigger must be stopped and removed immediately. Reactions of this type that do not have appropriate intervention may lead to respiratory distress. The airway and breathing must be assessed with this type of reaction, and appropriate intervention must be started immediately if needed. Treatment options also include antihistamines, steroids, or topical antipruritic agents. Epinephrine may also be used for serious reactions. Any identified triggers must be included as part of the patient’s health history. The patient and family should be educated to report this as a reaction to a food, medication, or other environmental trigger, and a medical alert bracelet may also be needed (Ricci et al., 2016).
Acne Vulgaris
Acne is a common inflammatory skin reaction causing pimples, papules, pustules, blackheads, whiteheads, cysts, or abscesses on various areas of the skin. These skin abnormalities vary in size, severity, and deepness into the skin layers. The common skin condition acne vulgaris is caused by bacteria, dead skin cells, or dried sebum that clogs hair follicles and prevents sebum from passing up through the pores (Figure 21.9). Acne triggers include puberty, polycystic ovarian syndrome, pregnancy, menstruation, hormonal disturbances, tight clothing, humidity, sweating, certain medications (e.g., anabolic steroids, corticosteroids), or various skin products (e.g., lotions, makeups, soaps). Identifying triggers can be difficult and may require making small changes at a time to determine the specific cause.
Mild acne includes blackheads, whiteheads, pimples, papules, and pustules and generally does not leave scars unless skin injury occurs when popping or squeezing the pimples. A flesh-colored, small bump with a dark center is a blackhead . A flesh-colored small bump that does not have a dark center is a whitehead . A pimple has a small area of red skin and can be painful or cause discomfort. A pustule is similar to a pimple but contains white or yellow pus. Severe acne is when patients have several blackheads, whiteheads, pimples, pustules, nodules, or deep acne (cystic acne). The cystic acne lesions are usually larger, red, painful, and pus-filled nodules that merge under the skin and often leave scars.
Acne generally lessens in severity by the midtwenties but may appear to those in their forties. This type of skin reaction can cause emotional stress and may require counseling. General care for acne includes washing daily with a mild soap, using water-based cosmetics, and eating a balanced diet low in processed carbohydrates. Inflammatory foods like gluten or dairy may need to be limited because they can cause acne for some individuals. Blackheads and whiteheads can be removed by comedone extraction . This is the use of a comedone extractor by a healthcare professional to incise the pore and then use gentle pressure around the pore opening with a wire loop.
There are also strips available at most pharmacies or grocery retailers for at-home extractions. Other treatment options include tretinoin cream (Retin-A), benzoyl peroxide (Acne-Clear), or antibiotics for blackheads, whiteheads, pimples, and pustules. Isotretinoin (Absorica) is effective for severe acne, and corticosteroids are effective for cystic acne. Other medications like oral contraceptives, spironolactone (Aldactone), and clascoterone (Winlevi) may also be used for hormonal acne. Acne scarring may be treated with a laser, microneedling, dermabrasion, collagen injections, or chemical peels (Keri, 2024).
Psoriasis
The recurring, chronic skin condition psoriasis causes one or more raised areas of red skin patches with silvery scales and a distinct border. Psoriasis is caused by an abnormally high rate of skin cell growth. This skin condition is immune mediated and often occurs because of a genetic predisposition. It can occur anywhere on the body. Various triggers may exacerbate this skin condition, but it is controllable. Flare-ups of psoriasis may be triggered by burns, colds or infections, stress, certain medications, cold weather, obesity, HIV, smoking, and inflammatory foods like gluten. Therapeutic management includes coal tar topical (Balnetar) shampoos, UV light, topical steroids, mineral oil, topical anti-inflammatories, emollient creams, immunosuppressants (e.g., methotrexate [Trexall]), and other medications (e.g., acitretin [Soriatane] and infliximab [Avsola]). Patients who have identifiable triggers may need to engage in lifestyle modifications, such as limiting cold exposure or eliminating inflammatory foods, such as sugar and high-fructose syrups (Das, 2023).
Systemic Lupus Erythematosus
The chronic autoimmune inflammatory disorder systemic lupus erythematosus (SLE) involves connective tissues of the joints, skin, kidneys, mucous membranes, and blood vessel walls. This skin disorder , also known as lupus, can be diagnosed with blood tests or other diagnostic testing. Sudden fever is often the first symptom of this condition. The rash is characterized by round, raised, and reddened areas that can lead to skin loss, scarring, and hair loss. This skin disorder may also include a butterfly-shaped reddened area across the nose and cheeks. Light-exposed areas (e.g., face, scalp) also have clusters of the rash. The rash may be flat or have psoriasis-like characteristics, and those affected may experience painful joints and fatigue. Migraines, mental disorders, epilepsy, and organ dysfunction may also occur. Patients with SLE may experience lung problems (e.g., pleural effusion), heart problems (e.g., pericarditis), enlarged lymph nodes or spleen, kidney failure, decreased blood cells or platelets, gastrointestinal problems (e.g., nausea, pancreatitis), or pregnancy complications (e.g., miscarriage, stillbirth) (Nevares, 2022). People with SLE often also experience Raynaud phenomenon , a condition that causes pale or blue fingers with cold exposure.
Flare-ups of lupus may be triggered by infection , pregnancy, surgery, or sun exposure . Early detection is optimal for a better prognosis and limiting the risks of kidney and other organ damage. Treatment options include hydroxychloroquine (Quineprox), nonsteroid anti-inflammatory drugs, corticosteroid creams, oral corticosteroids, and antimalarial or immunosuppressive medications. People who experience damage to other organs may require a transplant or dialysis, blood clots may need anticoagulants like warfarin (Coumadin), or complications of long-term steroid use may need vitamin D and calcium supplements to aid in preventing osteoporosis . People who have SLE should be closely monitored for diabetes and heart or kidney disease and should be educated on signs and symptoms. Pregnant women with SLE should be closely monitored to avoid flare-ups during pregnancy (Nevares, 2022).
Skin Cancer
The most common type of cancer is skin cancer , which has three main types: basal cell carcinoma, squamous cell carcinoma , and malignant melanoma (Figure 21.10). Patients with fair skin and lower melanin production and patients who spend significant time in the sun are at higher risk of all types of skin cancers. However, patients with darker skin and those who spend minimal time outdoors can still develop skin cancer.
Basal Cell Carcinoma
The most common type of skin cancer is basal cell carcinoma , and it is generally found on the head or neck. This type of skin cancer rarely metastasizes to other parts of the body but does invade and gradually destroy surrounding tissues. Basal cell carcinomas grow slowly and can go unnoticed because of the gradual change. These tumors can grow near the eyes, mouth, nose, or ears. They can be serious but are not usually fatal. Most tumors generally grow into the skin. The lesions are small, shiny bumps that may break open, form a scab, and sometimes bleed or flatten and look like scarring. Although a healthcare provider can easily identify this type of lesion, a biopsy should be performed to confirm the type of cancer. Treatment options include removal of the tumor by curettage and electrodesiccation, cutting it out, or cryosurgery . Topical chemotherapy medications may be applied to the skin. Other options include photodynamic therapy (using lasers and chemicals on the skin) and radiation therapy. Larger areas of basal cell carcinoma may require the MOHS procedure , where layers of the skin are removed and examined for cancer cells until no signs of cancer remain. The healthcare provider (often a dermatologist) may use sutures , skin flaps, or skin grafts to replace the removed skin or refer the patient to a plastic surgeon for closure (Nambudiri, 2024).
Squamous Cell Carcinoma
The second most common type of skin cancer is squamous cell carcinoma that generally develops on sun-exposed areas but can grow where sun exposure is limited. Squamous cell carcinoma is the cancer of squamous cells, keratinocytes, the main epidermal structural cells. This type of skin cancer is more likely with patients who have precancerous growths like actinic keratoses, scarred skin, and chronic mucus membrane or skin sores. This skin cancer generally starts as a red area with a crusted, scaly surface that may turn into a raised, firm wartlike surface. This lesion can become an open sore and grow into the underlying tissues. Biopsy is also best for diagnosing this type of cancer. The prognosis is generally excellent with early intervention. This type of cancer can metastasize and become fatal if not treated in time. Treatment options are similar to basal cell carcinoma but also include using an immune checkpoint inhibitor (e.g., PD-1 inhibitor [cemiplimab]). For patients who have large lesions that have metastasized or spread to the tissues underneath or cannot have surgery, PD-1 inhibitors help the body’s immune system annihilate the cancer (Nambudiri, 2024).
Malignant Melanoma
The most dangerous of the skin cancers is malignant melanoma that originates in the melanocytes. As sunlight increases melanin production, the risk of skin cancer increases. Melanoma metastasizes to distant parts of the body and can often go undetected, making it fatal. Those with undetected melanoma may not be diagnosed until affected organs of the body start displaying symptoms.
Melanoma may begin as a small, pigmented growth in a sun-exposed area or develop in a preexisting mole but can also occur in the mouth, on the genitals or rectal area, in the brain, in nail beds, or in or around the eyes. Risk factors for melanoma include those mentioned for other skin cancers but also include those with previous history of skin cancer, large number of moles, weakened immune system, fair skin, freckles, family history of melanoma, advanced age, and large congenital melanocytic nevus.
Melanomas usually are identifiable by an atypical mole with irregular borders and inconsistent colors. Some may be flat, irregular, brown patches with small black spots or can be raised brown patches with blue, black, red, or white spots. Melanoma can also be red, black, gray, and firm. A biopsy is needed for diagnosis. Nurses should understand the ABCDEs of melanoma and help educate patients on these warning signs (Table 21.6).
| Letter | Meaning | Examples |
|---|---|---|
| A | Asymmetry = two halves of a mole are not equal | |
| B | Borders = borders are irregular and seem to blend in or are not oval or round | |
| C | Color = existing mole changes color or moles that have drastically different colors than other moles present on the body | |
| D | Diameter = more than ¼ inch (0.6 cm) wide | |
| E | Evolution = mole that changes (bleeds, enlarges, becomes tender, itches) or development of a new mole after the age of 30 years |
Treatment options for melanoma are similar to options for the basal cell and squamous cell carcinoma s but also include targeted therapy and immunotherapy when the cancer has spread. Targeted therapy consists of medications that attack the cancer cell’s biologic mechanisms and include vemurafenib (Zelboraf) or binimetinib (Mektovi). Patients who have shallow melanomas may be treated with imiquimod cream (Aldara). Chemotherapy may also be needed if the cancer has spread or when no other treatment options are available. Treatment options may be used in combination with other treatments. Radiation therapy is often used when complete removal of the tumor is not achievable or when it has metastasized to the brain (Nambudiri, 2024). If the melanoma is aggressive and has been deemed untreatable or incurable, the patient may need to receive comfort care or hospice care.
Everyone should be screened regularly for skin cancer by a healthcare provider or dermatologist. Nurses should take any opportunity to educate people about sun exposure and ways to help prevent skin cancer. A key point to educate patients on is how to observe changes or unusual skin markings that they should report to their healthcare provider. Additionally, nurses should educate patients about avoiding the sun or seeking shaded areas, especially when the sun’s rays are the strongest (between 10 a.m. and 4 p.m.), wearing sunscreen with an SPF factor of at least thirty or greater, wearing protective clothing (e.g., hats, sunglasses, long sleeves), and avoiding the use of tanning beds (Nambudiri, 2024).
Scenario: A nurse is performing an annual checkup on a patient who subsequently states they have been an avid tanning bed user for more than thirty years.
Nurse: Hi. My name is Susie, and I will be your nurse today. May I have your name and date of birth?
Patient: Yes. Hi, my name is Tiffany Ball, date of birth is May 12, 1975.
Nurse: What medications are you currently taking?
Patient: None.
Nurse: Any known medication allergies?
Patient: No.
Nurse: The last time we saw you, your surgical history included a cesarean section. Is that correct? Any other surgeries?
Patient: Nope. Just that one so far.
Nurse: Thank you. Have you noticed any new spots on your skin or anything that may concern you?
Patient: I have not noticed anything.
Nurse: Okay, well if you are ready, I will let the provider know you are ready for the skin check.
[The provider comes in and, while performing the annual examination, notices a suspicious mole on the patient’s upper back. The provider removes it with the patient’s permission and sends it off to pathology for a biopsy. The provider leaves the room.]
Patient: Wow. So, what causes skin cancer? I hardly go outside.
Nurse: Do you have a family history of skin cancer? Do you use tanning beds?
Patient: I think my dad had a spot removed a few years ago. I have been tanning in a tanning bed since high school, so maybe thirty years or so. I was told a tanning bed was safer.
Nurse: Tanning beds do increase your risk of developing skin cancer due to the UV rays (e.g., UVA and UVB) that may be used in a tanning bed.
Patient: Oh, so since I already have a spot anyway, I can still tan, right?
Nurse: Your results will come back from the laboratory, and then we can confirm whether or not it is cancerous. It is best to minimize your risks for skin cancer . Just because you have one potential spot does not mean you could not have another. The risks for skin cancer include family history and sun exposure , especially between 10 a.m. and 4 p.m. If you are going to be in the sun, use sunscreen with an SPF of at least thirty, find shade often, and wear protective clothing like long sleeves, pants, and wide-brimmed hats.
Patient: So, what are you saying about using tanning beds?
Nurse: Tanning beds do not offer a safe alternative to sunlight. Unfortunately, they also increase the risk for skin cancers, including melanoma, the deadliest form of skin cancer.
Health Promotion and Behavioral Considerations
Health promotion as it relates to skin integrity includes lifestyle choices and behaviors that promote healthy skin. Those with impaired skin integrity should be careful with their hygiene practices and behaviors to avoid further aggravating their skin conditions. Some behaviors that help protect the skin include the following:
- using pH-balanced or mild soaps when bathing
- patting dry versus rubbing, which makes skin more prone to friction tears or other skin damage
- using emollients that moisturize and soften the skin
- avoiding the use of detergents that contain fragrance
- avoiding the use of deodorant soaps
- eliminating triggers
Any possible infectious skin lesions should be observed for signs of improvement or worsening. Drainage is a possibility from skin lesions; therefore, nurses should follow standard and transmission-based precautions when assessing the skin or changing dressings. Standard precautions may include wearing gloves, gowns, masks, or face shields as needed and disposing of them properly after use. Any contaminated dressings should also be disposed of according to organizational policies. Patients who have lesions may need to be educated on proper at-home wound care (see 8.3 Wound Management).
Nurses should educate patients and families on adequate hygiene and proper skin care (see Chapter 7 Hygiene) for prevention of impaired skin integrity. Other behaviors that promote adequate skin integrity should also include understanding the importance of routine skin checks, minimizing sun exposure during the time of day when the UV rays are the strongest, wearing protective clothing while in the sun, and using sunscreen. Age-related and cultural considerations should be taken into consideration when educating on health promotion behaviors for impaired skin integrity.
Age-Related Considerations
Newborns have thinner skin that is more sensitive and susceptible to rashes (e.g., contact dermatitis), newborn acne, and seborrheic dermatitis . Newborns cannot care for themselves; therefore, caregivers should be educated on the need to keep the newborn and caregiver nails trimmed to avoid scratching the baby. They should also be educated on signs and symptoms of common skin irritations as well as prevention actions and treatment options.
Toddlers and preschoolers are more prone to accidents because of their high activity levels and difficulties with mobility . They may fall or run into inanimate objects which may lead to lacerations, burns, or other abrasions. Caregivers should be educated to implement safety precautions to prevent injuries. For example, padding sharp corners may prevent accidents.
Head lice, impetigo, scabies, and rashes are more common in school-age children and adolescents. Acne vulgaris generally starts during adolescence and can lead to an impaired body image, which may require counseling. This age group typically wants to be more independent, so education may be needed to ensure proper skin care.
Skin changes as people age (see 21.1 Structure and Functions of the Skin). Older adults should focus on adequate nutrition and hydration, especially ensuring adequate protein intake to promote wound healing . Older adults may have impaired mobility making adequate hygiene difficult or impossible for this age group to perform. Therefore, it is important that the nurse or caregiver promote appropriate skin care, prevention, and intervention with impaired skin integrity . Some skin changes are benign like cherry angiomas, seborrheic keratoses, spider angiomas, wrinkles, dryness ( xerosis ), neurodermatitis, liver spots, melasma, telangiectasias (red marks on the skin caused by widening of shallow blood vessels), and hair loss.
Skin in the very young is more fragile and thinner than the skin of an adult. The skin and mucous membranes are more susceptible to injury and infection . As the child ages, their skin becomes more resistant to infection and injury. Special care is needed when handling and caring for infants to prevent harm. For example, a baby’s fingernails should be filed or mittens worn to prevent the infant from scratching themself. Additionally, infants must be bathed in lukewarm water to prevent burn injuries.
Cultural-Related Considerations
Nurses should remember that cultural considerations regarding skin conditions are common but may be different among various cultures and ethnic groups (see 21.1 Structure and Functions of the Skin). Patients with fair skin produce less melanin and are more at risk of skin cancer s than darker-skinned individuals. However, patients with darker skin are more susceptible to postinflammatory hyperpigmentation , dermatosis papulose nigra , keloids, hair loss, pityriasis , vitiligo , and dry skin. Other considerations include cultures that may not believe in medical interventions. For example, people who follow the Amish religion may not believe in accepting outside medical care or interventions. The nurse should not make assumptions but should assess beliefs and preferences as well as provide education to the patient and their family members regarding the skin disorder , treatment options, and risks of not being treated. The patient should be allowed to decide what interventions they do or do not want to receive without bias from the nurse. The nurse should also analyze a patient’s cultural preferences when developing a plan of care to promote healing and improve skin integrity.


13.1: Orbits
Types of Orbits Under an Inverse-Square Force
Consider a system formed by two particles (or two perfect, rigid spheres) interacting only with each other, through their gravitational attraction. Conservation of the total momentum tells us that the center of mass of the system is either at rest or moving with constant velocity. Let us assume that one of the objects has a much greater mass, \(M\), than the other, so that, for practical purposes, its center coincides with the center of mass of the whole system. This is not a bad approximation if what we are interested in is, for instance, the orbit of a planet around the sun. The most massive planet, Jupiter, has only about 0.001 times the mass of the sun.
Accordingly, we will assume that the more massive object does not move at all (by working in its center of mass reference frame, if necessary—note that, by our assumptions, this will be an inertial reference frame to a good approximation), and we will be concerned only with the motion of the less massive object under the force \(F = GMm/r^2\), where \(r\) is the distance between the centers of the two objects. Since this force is always pulling towards the center of the more massive object (it is what is often called a central force ), its torque around that point is zero, and therefore the angular momentum, \(\vec L\), of the less massive body around the center of mass of the system is constant. This is an interesting result: it tells us, for instance, that the motion is confined to a plane , the same plane that the vectors \(\vec r\) and \(\vec v\) defined initially, since their cross-product cannot change.
In spite of this simplification, the calculation of the object’s trajectory, or orbit , requires some fairly advanced mathematical techniques, except for the simplest case, which is that of a circular orbit of radius \(R\). Note that this case requires a very precise relationship to hold between the object’s velocity and the orbit’s radius, which we can get by setting the force of gravity equal to the centripetal force:
\[ \frac{G M m}{R^{2}}=\frac{m v^{2}}{R} \label{eq:10.11} .\]
So, if we want to, say, put a satellite in a circular orbit around a central body of mass \(M\) and at a distance \(R\) from the center of that body, we can do it, but only provided we give the satellite an initial velocity \(v=\sqrt{G M / R}\) in a direction perpendicular to the radius. But what if we were to release the satellite at the same distance \(R\), but with a different velocity, either in magnitude or direction? Too much speed would pull it away from the circle, so the distance to the center, \(r\), would temporarily increase; this would increase the system’s potential energy and accordingly reduce the satellite’s velocity, so eventually it would get pulled back; then it would speed up again, and so on.
You may experiment with this kind of thing yourself using the PhET demo at this link:
https://phet.colorado.edu/en/simulation/gravity-and-orbits
You will find that, as long as you do not give the satellite—or planet, in the simulation—too much speed (more on this later!) the orbit you get is, in fact, a closed curve, the kind of curve we call an ellipse . I have drawn one such ellipse for you in Figure \(\PageIndex{3}\).
Figure \(\PageIndex{3}\): An elliptical orbit. The semimajor axis is \(a\), the semiminor axis is \(b\), and the eccentricity \(e=\sqrt{1-b^{2} / a^{2}}\) = 0.745 in this case.. The “center of attraction” (the sun, for instance, in the case of a planet’s or comet’s orbit) is at the point O.
As a geometrical curve, any ellipse can be characterized by a couple of numbers, \(a\) and \(b\), which are the lengths of the semimajor and semiminor axes, respectively. These lengths are shown in the figure. Alternatively, one could specify \(a\) and a parameter known as the eccentricity , denoted by \(e\) (do not mistake this “\(e\)” for the coefficient of restitution of Chapter 4!), which is equal to \(e=\sqrt{1-b^{2} / a^{2}}\). If \(a\) = \(b\), or \(e\) = 0, the ellipse becomes a circle.
The most striking feature of the elliptical orbits under the influence of the \(1/r^2\) gravitational force is that the “central object” (the sun, for instance, if we are interested in the orbit of a planet, asteroid or comet) is not at the geometric center of the ellipse. Rather, it is at a special point called the focus of the ellipse (labeled “O” in the figure, since that is the origin for the position vector of the orbiting body). There are actually two foci, symmetrically placed on the horizontal (major) axis, and the distance of each focus to the center of the ellipse is given by the product \(ea\), that is, the product of the eccentricity and the semimajor axis. (This explains why the “eccentricity” is called that: it is a measure of how “off-center” the focus is.)
For an object moving in an elliptical orbit around the sun, the distance to the sun is minimal at a point called the perihelion, and maximal at a point called the aphelion. Those points are shown in the figure and labeled “P” and “A”, respectively. For an object in orbit around the earth, the corresponding terms are perigee and apogee; for an orbit around some unspecified central body, the terms periapsis and apoapsis are used. There is some confusion as to whether the distances are to be measured from the surface or from the center of the central body; here I will assume they are all measured from the center, in which case the following relationships follow directly from Figure \(\PageIndex{3}\):
The ellipse I have drawn in Figure \(\PageIndex{3}\) is actually way too eccentric to represent the orbit of any planet in the solar system (although it could well be the orbit of a comet). The planet with the most eccentric orbit is Mercury, and that is only \(e\) = 0.21. This means that \(b\) = 0.978\(a\), an almost imperceptible deviation from a circle. I have drawn the orbit to scale in Figure \(\PageIndex{4}\), and as you can see the only way you can tell it is an ellipse is, precisely, because the sun is not at the center.
Figure \(\PageIndex{4}\): Orbit of Mercury, with the sum approximately to scale
Since an ellipse has only two parameters, and we have two constants of the motion (the total energy, \(E\), and the angular momentum, \(L\)), we should be able to determine what the orbit will look like based on just those two quantities. Under the assumption we are making here, that the very massive object does not move at all, the total energy of the system is just
\[ E=\frac{1}{2} m v^{2}-\frac{G M m}{r} \label{eq:10.13} .\]
For a circular orbit, the radius \(R\) determines the speed (as per Equation (\ref{eq:10.11})), and hence the total energy, which is easily seen to be \(E=-\frac{G M m}{2 R}\). It turns out that this formula holds also for elliptical orbits, if one substitutes the semimajor axis \(a\) for \(R\):
\[ E=-\frac{G M m}{2 a} \label{eq:10.14} .\]
Note that the total energy (\ref{eq:10.14}) is negative . This means that we have a bound orbit, by which I mean, a situation where the orbiting object does not have enough kinetic energy to fly arbitrarily far away from the center of attraction. Indeed, since \(U^G \rightarrow 0\) as \(r \rightarrow \infty\), you can see from Equation (\ref{eq:10.13}) that if the two objects could be infinitely far apart, the total energy would eventually have to be positive, for any nonzero speed of the lighter object. So, if \(E < 0\), we have bound orbits, which are ellipses (of which a circle is a special case), and conversely, if \(E > 0\) we have “unbound” trajectories, which turn out to be hyperbolas 4 . These trajectories just pass near the center of attraction once, and never return.
The special borderline case when \(E\) = 0 corresponds to a parabolic trajectory. In this case, the particle also never comes back: it has just enough kinetic energy to make it “to infinity,” slowing down all the while, so \(v \rightarrow 0\) as \(r \rightarrow \infty\). The initial speed necessary to accomplish this, starting from an initial distance \(r_i\), is usually called the “escape velocity” (although it really should be called the escape speed), and it is found by simply setting Equation (\ref{eq:10.13}) equal to zero, with \(r = r_i\), and solving for \(v\):
\[ v_{e s c}=\sqrt{\frac{2 G M}{r_{i}}} \label{eq:10.15} .\]
In general, you can calculate the escape speed from any initial distance \(r_i\) to the central object, but most often it is calculated from its surface. Note that \(v_{esc}\) does not depend on the mass of the lighter object (always assuming that the heavier object does not move at all). The escape velocity from the surface of the earth is about 11 km/s, or 1.1×10 4 m/s; but this alone would not be enough to let you leave the attraction of the sun behind. The escape speed from the sun starting from a point on the earth’s orbit is 42 km/s.
To summarize all of the above, suppose you are trying to put something in orbit around a much more massive body, and you start out a distance \(r\) away from the center of that body. If you give the object a speed smaller than the escape speed at that point, the result will be \(E\) < 0 and an elliptical orbit (of which a circle is a special case, if you give it the precise speed \(v=\sqrt{G M / r}\) in the right direction). If you give it precisely the escape speed (\ref{eq:10.15}), the total energy of the system will be zero and the trajectory of the object will be a parabola; and if you give it more speed than \(v_{esc}\), the total energy will be positive and the trajectory will be a hyperbola. This is illustrated in Figure \(\PageIndex{5}\) below.
Figure \(\PageIndex{5}\): Possible trajectories for an object that is “released” with a sideways velocity at the lowest point in the figure, under the gravitational attraction of a large mass represented by the black circle. Each trajectory corresponds to a different value of the object’s initial kinetic energy: if \(K_{circ}\) is the kinetic energy needed to have a circular orbit through the point of release, the figure shows the cases \(K_i = 0.5K_{circ}\) (small ellipse), \(K_i = K_{circ}\) (circle), \(K_i = 1.5K_{circ}\) (large ellipse), \(K_i = 2K_{circ}\) (escape velocity, parabola), and \(K_i = 2.5K_{circ}\) (hyperbola).
Note that all the trajectories shown in Figure \(\PageIndex{5}\) have the same potential energy at the “point of release” (since the distance from that point to the center of attraction is the same for all), so increasing the kinetic energy at that point also means increasing the total energy (\ref{eq:10.13}) (which is constant throughout). So the picture shows different orbits in order of increasing total energy.
For a given total energy, the total angular momentum does not change the fundamental nature of the orbit (bound or unbound), but it can make a big difference on the orbit’s shape. Generally speaking, for a given energy the orbits with less angular momentum will be “narrower,” or “more squished” than the ones with more angular momentum, since a smaller initial angular momentum at the point of insertion means a smaller sideways velocity component. In the extreme case of zero initial angular momentum (no sideways velocity at all), the trajectory, regardless of the total energy, reduces to a straight line, either straight towards or straight away from the center of attraction.
For elliptical orbits, one can prove the result
\[ e=\sqrt{1-\frac{L^{2}}{a G M m^{2}}} \label{eq:10.16} \]
which shows how the eccentricity increases as \(L\) decreases, for a given value of \(a\) (which is to say, for a given total energy). I should at least sketch how to obtain this result, since it is a variant of a procedure that you may have to use for some homework problems this semester. You start by writing the angular momentum as \(L = mr_Pv_P\) (or \(mr_Av_A\)), where \(A\) and \(P\) are the special points shown in Figure \(\PageIndex{3}\), where \(\vec v\) and \(\vec r\) are perpendicular. Then, you note that \(r_P = r_{min} = (1 − e)a\) (or, alternatively, \(r_A = r_{max} = (1 + e)a\)), so \(v_P = L/[m(1− e)a]\). Then substitute these expressions for \(r_P\) and \(v_P\) in Equation (\ref{eq:10.13}), set the result equal to the total energy (\ref{eq:10.14}), and solve for \(e\).
Figure \(\PageIndex{6}\): Effect of the "angle of insertion" on the orbit.
Figure \(\PageIndex{6}\) illustrates the effect of varying the angular momentum, for a given energy. All the initial velocity vectors in the figure have the same magnitude, and the release point (with position vector \(\vec r_i\)) is the same for all the orbits, so they all have the same energy; indeed, you can check that the semimajor axis of the two ellipses is the same as the radius of the circle, as required by Equation (\ref{eq:10.14}). The difference between the orbits is their total angular momentum. The green orbit has the maximum angular momentum possible at the given energy, since the green velocity vector is perpendicular to \(\vec r_i\). Note that this (maximizing \(L\) for a given \(E\) < 0) always results in a circle, in agreement with Equation (\ref{eq:10.15}): the eccentricity is zero when \( L=L_{c i r c} \equiv \sqrt{a G M m^{2}}\), which is the largest value of \(L\) allowed in Equation (\ref{eq:10.15}).
For the other two orbits, \(\vec v_i\) and \(\vec r_i\) make angles of 45\(^{\circ}\) and 135\(^{\circ}\), and so the angular momentum \(L\) has magnitude \(L=L_{\text {circ}} \sin 45^{\circ}=L_{\text {circ}} / \sqrt{2}\). The result are the red and blue ellipses, with eccentricities \(e=\sqrt{1-\sin ^{2}\left(45^{\circ}\right)}\) = 0.707.
4 There is apparently a way to describe a hyperbola as an ellipse with eccentricity \(e\) > 1, but I’m definitely not going to go there.


3.1.3: Paper- Popular Culture is Killing Writing
Author: Bronwyn T. Williams, English, University of Louisville
For more than a century, common sense has been telling us that popular culture is killing writing. In 1887, Adams Sherman Hill, of Harvard, bemoaned the effect of popular culture on writing this way: “To read nothing but newspapers and second-rate novels is surely a waste of time... (and) tends to weaken the powers of attention and concentration, to diminish, if not destroy, freshness of thought and individuality of expression.” While the culprits have changed over the years, from newspapers to movies to television in the 20th-century, to digital games and social media today, the concerns and complaints remain remarkably the same. Popular culture texts, according to these laments, are intellectually undemanding, too reliant on emotion, too informal, and often morally compromising (the last was also a concern of Hill’s). Students who read too many comics, watch too much television, or play too many digital games, according to this narrative, will produce naïve, emotional writing that is riddled with errors.
Curiously, however, literacy has not disappeared in the years since Hill developed the foundational first-year writing course at Harvard, to combat the poor writing he attributed in part to popular culture. Literacy rates continue to increase in the U.S., as do the number of words people read and write every year, thanks to the rise in online writing. In university classrooms, as Stanford University’s Andrea Lunsford demonstrates in her research, undergraduate writing students are not only writing longer papers in their courses today, they are making fewer errors of usage and style. Clearly, popular culture has not led to a generation of illiterate people. What’s more, popular culture is not, in itself, the cause of poor writing and when young people engage with popular culture they are learning valuable rhetorical concepts and skills.
Yet when I tell people, whether members of the public or other writing teachers, that popular culture is not the nemesis of writing they assume it to be—and I’ve been researching the interplay of popular culture and student writing for close to twenty years— they can’t believe what I’m saying is true. Across the political spectrum, they are convinced that popular culture is killing writing. Critics on the right fear the intellectual and moral laxity of popular culture, while those on the left fault popular culture for reinforcing harmful stereotypes and brainwashing them into becoming mindless consumers. Across the board, they are convinced that popular culture harms writing because it is too easy to understand and students learn nothing from it. In short, popular culture wastes time and minds. People complain that students refuse to read novels, or that they write emails containing typos, or that they include text-speak in college papers.
Even though research contradicts these anecdotal experiences, these narratives persist for several reasons. For one thing, research on memory and narrative makes it clear that all of us are notoriously bad at accurately remembering how we learned things, or how we struggled to learn things, when we were younger. In addition, people tend to distrust or discount new technologies and media with which they are unfamiliar, while maintaining nostalgia for what they did as youth. As Mitchell Stephens notes, in tracing the complaints that have accompanied new communication media dating back to the Gutenberg printing press (and including the telephone, pencils, and television, among others), “We rarely trust the imposition of a new magic on our lives, and we rarely fail to work up nostalgia for the older magic it replaces.” Such nostalgia leads to narratives of a perpetual literacy crisis that are remarkably consistent decade after decade.
Perhaps most important, however, is the general misunderstanding of how people acquire rhetorical and literate abilities, particularly as they move from one genre or medium to another. A substantial, and growing, body of research on the relationship between popular culture and writing shows time and again students engaging in literacy practices that are complex and constantly evolving. There are ways in which popular culture helps student writers, some ways in which it doesn’t seem to make much difference, and, yes, some ways in which it collides with the writing students do in school.
One prevailing myth about popular culture is that it is easy or simple and that’s why young people like it. It’s true that some movies or video games or television programs are not all that challenging in content or form. The same can be said of many books, plays, and poems. Even as critics of popular culture find it easy to summon uncomplicated reverence for established media and genres, such as the print novel, the reality is that there is no medium or genre in which every work is a masterpiece, and no medium or genre that cannot carry substantial intellectual insights. Young people talk to me and other researchers about being heavily invested in popular culture such as television series, comics, movies, and games that are complex, innovative, and engaging their minds. People who still think television is a vast wasteland aren’t watching series such as The Americans or Westworld , with their complex characters and narrative structures. People who think all computer games are mindless and don’t require thought haven’t played the range of games I see students playing, which require diligence, creativity, and learning to complete.
The reason students read popular culture with facility and enthusiasm, including complex and sophisticated forms, is not a matter of simplicity, it’s a matter of practice. Learning how to navigate any genre takes time and practice to figure out how it works. Think about the first time you tried to figure out something in a genre with which you had little practice, whether it was a legal contract, poem, opera, or heavy metal. It probably slowed you down, was a bit confusing, and was neither pleasurable nor confidence building. Yet, if you had more practice, your familiarity and facility would increase. There is no doubt that, for the great majority of students, they have much, much more practice reading and making sense of popular culture than they do with academic articles or textbooks. Although, it is also the case that, for every student, there are genres of popular culture they do not have much experience with and are not able to make sense of easily. When I talk with students about popular culture, it is not long before they’ll tell me of a form or genre that they just think is weird or that they don’t get, whether it’s hip hop or country music or horror films or Twitter. It is practice with reading and interpreting genres that has developed their skills in reading, movies, popular music, television, computer games, social media, and more. They read with ease, but not because the content is always easy.
The ease with which students can interpret a form of popular culture has developed with practice, which at some point included struggle, help from others, and accumulating knowledge—in other words, learning. Another myth about popular culture and writing
is that people learn nothing from it. Students learn a tremendous amount about rhetoric and communication from their engagement with popular culture, most notably about rhetorical concepts such as genre, audience, and style. When researchers talk with students about their popular culture reading, the students talk knowledgeably and even critically about these rhetorical aspects. Students may talk about a romantic comedy in terms of genre conventions, for example, discussing the kinds of character types that typically show up, whether as protagonists or sidekicks. Or, ask students to discuss the people who frequent an online popular culture discussion forum and they will be able to describe the audience there, as well as the kinds of posts that are viewed positively or negatively. Young people may not always discuss these elements using the specific terms we use in academic settings, but they are familiar with these key rhetorical concepts.
It is not the case that the rhetorical abilities students learn through their extensive engagement with popular culture transfer seamlessly to their classroom writing. Like any of us learning to write in a new genre, students need writing classes that help them understand the conventions, and the reasons for the conventions, of that new genre. Still, when we talk with students about key rhetorical concepts of audience, genre, and style—elements crucial to negotiating any writing situation—we need to understand that students enter the classroom with a vast range of experiences with these concepts. If we help students understand and articulate the knowledge they have learned from popular culture in terms of audience, genre, and style, it is easier to get them to consider how all writing works within particular genre conventions. If we can help them see how they have learned the conventions of popular culture through practice and discussion, they can see how they can do the same if they learn and practice the conventions of academic texts. I should also note that when students understand more about genre and rhetoric, they also become more creative and critical readers and writers of popular culture. Learning is best when the bridge goes both ways.
People do not necessarily connect the ideas of guidance and instruction to how students learn popular culture. Certainly, it is true that young people are exposed to some popular culture forms, such as television, from an early age and do not need to learn how to interpret many television programs in the same way they have had to learn to read. On the other hand, there are popular culture forms, such as computer games, that take more explicit instruction and guidance to learn. Even within familiar forms such as television or music, new genres and unusual songs or programs can be confusing to young people. They do, in fact, need instruction or guidance to help them with their struggles to understand unfamiliar popular culture. At these moments students typically turn to their peers for advice. You don’t need to spend much time around young people before you can hear them arguing about, or explaining to each other, the meaning of a song or movie. The development of online forums has offered another popular source of advice and guidance. Research with students with a variety of interests demonstrates that they go to online forums about everything from computer games, to music, to movies for reviews, tips, or discussions. It is important to remember that these discussions happen through writing and reading.
Indeed, one of the results of the advent of an online, participatory popular culture is that it has led to an explosion of reading and writing. Although there are other modes of communication online, such as video, there is still a tremendous amount of reading and writing taking place in online spaces. In fact, compared with thirty years ago, when television and film dominated popular culture practices, young people today are engaged in significantly more reading and writing. What they are learning from writing and reading in online spaces is, again, a more sophisticated and critical appreciation of concepts of audience, genre, and style, as well as concepts of authorial presence, collaboration, and remix. If you make the time and effort to listen to young people who write and read online, they can talk at length and with insight about how, for example, they consider audience and their online persona when creating a social media profile and posting comments on that page.
Again, when students talk about rhetorical concepts such as audience or genre, they may not articulate their knowledge using these terms unless we make that connection for them. Even so, they do understand the effect of rhetoric on communication. They understand that context influences the choices they make when communicating, and consequently they usually understand that they should use different rhetorical approaches in different contexts. I have not interviewed or observed a single student over the years who did not understand that there were differences in expectations for genre and style between posting an update on social media and writing an essay for a university course. They understand that they are supposed to switch from popular culture genres and language use when writing for a course. (Indeed, linguist David Crystal, among others, demonstrates that stories of students incorporating text-speak in academic papers is largely an urban myth.) That students understand that writing in an academic setting necessitates a different kind of writing than popular culture does not mean they can do so automatically and effortlessly. Learning to write in a new genre always results in uneven moments of struggle and a tendency to make more errors of usage. Still, the issue is switching from one genre to another, not that one of the genres happens to be some form of popular culture.
Finally, while this is not the place to address concerns people have about the effects of popular culture on morality, I do want to challenge the idea that popular culture makes young people lazy and shortens their attention spans. Simply put, how do we reconcile the argument about shorter attention spans with young people flocking to popular movies that are more than three hours long, or playing video games for hours until solving a particular problem, or reading book series such as Harry Potter or The Hunger Games that run for thousands of pages? Instead, we should ask why they are willing to spend so much time and effort on these popular culture texts and yet are often less interested in lengthy academic texts. One reason, as I noted above, is that having had more practice with popular culture they are able to engage with it more skillfully. Yet, another reason for the appeal of popular culture for students is that the movies, games, and music they engage with on their own time are usually under their control. Students’ interpretations of popular culture are not dictated by their parents or evaluated by their teachers. According to researchers on motivation, control over our activities and of the meaning we make of those activities usually increases our motivation to engage in such activities. We rarely take as much pleasure in work that is assigned to us as in projects that we engage in by choice. Perhaps rather than fretting about popular culture we should be worrying more about the damage that relentless standardized assessment is having on student motivation.
Please understand, I am not going down the road to “everything that is bad is actually good for you.” Popular culture can be problematic in many ways. The representations of gender and race and violence can be deeply disturbing, as can cynical appeals to emotion—from advertisements to cable news talk shows. What’s more, the kind of extended, evidence-based argument common in academic writing is much rarer in popular culture, where narrative and collage are much more prevalent rhetorical forms. Students who have more of their experience reading and writing popular culture will have some learning to do in college to practice and master the genres of writing expected there. The point is, however, that students would have to learn to read and write in new genres when they get to university, regardless of the genre knowledge they had when they arrived on campus.
If we understand this last point—that students will always have to learn, and struggle with, writing in new genres at university—then we can understand why popular culture, regardless of the form, has been the source of so much complaint for more than a century. Too many people still believe that you can be taught to write once, and that such knowledge should serve you for the rest of your life. First-year writing courses are often regarded as providing the single inoculation for writing—and against popular culture—that students need. Instead, we must understand that writing and reading are abilities that we acquire through learning and practice, and that we never stop learning them. The more we are immersed in texts, the richer understanding we have of the genre, style, audience, and rhetorical context for which they were produced. Students are adept at reading and writing popular culture because they practice it, learn it, control it. Given the same conditions, and motivation, they can learn to do the same with other forms of writing.
Further Reading
For more about the many literacies that students negotiate in and out of school, see Daniel Keller’s Chasing Literacy: Reading and Writing in an Age of Acceleration or Jennifer Rowsell’s Working with Multimodality: Rethinking Literacy in the Digital Age , along with these collections of essays, listed by editors’ names: Donna Alvermann and Kathleen Hinchman’s Reconceptualizing the Literacies in Adolescents’ Lives (3rd ed.); Cathy Burnett et al.’s New Literacies around the Globe: Policy and Pedagogy ; Ito Mizuko et al.’s Hanging Out, Messing Around, and Geeking Out: Kids Living and Learning with New Media ; or Marc Lamont Hill and Lalitha Vasudevan’s Media, Learning, and Sites of Possibility . I have also written about these subjects in Shimmering Literacies: Popular Culture and Reading and Writing Online ; Tuned In: Television and the Teaching of Writing ; and New Media Literacies and Participatory Popular Culture Across Borders (co-edited with Amy Zenger). To learn more about fan communities, identity, and online writing, see Rebecca Black’s Adolescents and Online Fan Fiction and Angela Thomas’s Youth Online: Identity and Literacy in the Digital Age .
Keywords
fan communities, genre, participatory culture, popular culture, remix
Author Bio
Bronwyn T. Williams is a professor of English and director of the University Writing Center at the University of Louisville. He has taught writing and studied the connections between popular culture and students’ writing and reading practices, both in the U.S. and abroad, for more than 25 years. He is the author of a number of books on the teaching of writing, popular culture, and student identity. Twitter: @bronwyntw. Website: bronwyntwilliams.com.


20.2: Description
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Your instructional strategy should describe the instructional materials’ components and procedures used with the materials that are needed for students to achieve the learning outcomes. The strategy should be based on the learning outcomes and information from the other previous instructional design steps. You can even base your strategy on how you or others have solved similar problems. You can save time and money by not re-inventing the wheel. However, be careful; a lot of existing instructional material is designed poorly.
At the end of this process, you should have a clear set of specifications describing how the material will be taught. This can include a flowchart representing the instructional pathway. You will use the instructional strategy as a framework for further developing the instructional materials or evaluating whether existing materials are suitable or need revision. As a general rule, use the strategy to set up a framework for maximizing effective and efficient learning. This often requires using strategies that go beyond basic teaching methods. For example, discovery-learning techniques can be more powerful than simply presenting the facts. One common pitfall in creating online lessons is teaching in the same way as was done with traditional methods. If this is done, then there may only be minimal value in transferring the material to an online system. As Emile Chartier said, “Nothing is more dangerous than an idea, when it is the only one you have.” Note that you can address a variety of learning styles if you teach with a variety of different methods and media. No one single teaching method or medium is ideal for all learners.
As you proceed through developing an instructional strategy, start specifying the media that would most effectively teach the material. (Read Chapter 21, Media Selection, for more information.)


6.16: Specialty Speeches- Pecha Kucha, Ignite, Moth
PechaKucha is the Japanese word for chit-chat. It is a storytelling format where each speaker presents 20 slides that advance automatically after 20 seconds.
It was originally used by Astrid Klein and Mark Dytham to streamline long design presentations and more recently it has been used for PechuKucha Nights where people gather and share inspirational stories.
20 slides. 20 seconds of commentary.
For more Pecha Kucha, check out there website.
https://www.pechakucha.com/
IGNITE TALKS
Ignite talks are likely inspired by Pechakucha (and are much easier to pronounce). Their tagline is “Enliven us, but make it quick.” Presenters get 20 slides that automatically
advance every 15 seconds. The total presentation lasts 5 minutes.
For more information on Ignite Talks
http://www.ignitetalks.io/