Lexicon for Atopic Dermatitis

This is a lexicon for Atopic Dermatitis.
Click on a letter and discover all the related terms and their definition.

  • EASI


    Eczema Area and Severity Index This is a scale that helps to rate the surface and severity of atopic dermatitis. The EASI score is often used by American dermatologists for clinical trials. In Europe, the more commonly used scale is the SCORAD.  
  • Eczema herpeticum


    This Latin term is used in medical texts to describe severe herpes which can complicate atopic dermatitis. In French, it is often known as "Kaposi-Juliusberg varioloform pustules". 
    Basically, atopic skin is particularly vulnerable to infection by the herpes virus. This is not too serious, but most often requires oral antiviral treatment. 
  • Eczema of the eyelids


    The skin of the eyelids is particularly thin and is thus subject to eczema reactions. Atopic dermatitis in older children and adults often affects the eyelids.
    A classic cause of eczema of the eyelids is allergy to nail varnish. The nails themselves are not affected due to their thickness, however the thinnest areas of skin that are touched by the fingers (neck, eyes, etc.) can present with eczema lesions. 
  • Eczematides


    A vague dermatological term describing non-acute eczema. 
    Atopy sufferers may present with eczematide-like eruptions.   
  • Edema


    Swelling caused by the presence of liquid in tissues. Swollen legs in patients presenting with venous insufficiency is an example of edema.  There is no significant edema in atopic dermatitis, because the liquid caused by inflammation is able to escape the skin as weeping
  • Egg allergy


    Allergy to egg is one of the major food allergies. Certain children with atopy are allergic to eggs. But as always with allergies, one should be careful not to confuse positive tests with real allergy, and remember that aside from cases with digestive complaints, it is pointless to test atopy sufferers for food allergies. 
  • Elimination diet


    Removal of a specific foodstuff from a child's diet. 
    A real allergy to one type of food justifies the removal of this food from the child's diet.  
    However, food should not be eliminated without a medical reason. Elimination diets are not necessary for atopic dermatitis, unless the patient also suffers from digestive difficulties, and has had an accurate allergological and nutritional examination. Remember that food allergies are very rare in children who are affected with atopic dermatitis with no digestive symptoms.
  • Emollient

    An emollient is a cream or ointment that moisturizes and softens the skin.

  • Emollients


    Locally-applied products that increase the skin's hydration (emollient and moisturizer are practically synonymous). Emollients often have a 'cosmetic' (or dermo-cosmetic) product status. Currently, some emollients have a medical device or even drug status. These regulatory distinctions have no major practical impact. Atopic dermatitis involves dry skin (atopic xerosis) and emollients are thus an important part of treatment. 
  • Eosinophils


    One of the categories of polynuclear blood cells (or white blood cells). The number of eosinophils in the blood is increased in parasitic conditions, allergic conditions, and certain rare diseases. In atopic dermatitis, there is often a moderate increase in blood eosinophils, with no practical impact. 
  • Epicutaneous tests


    See Patch tests.
  • Epidermal barrier

    (or skin barrier)
    The skin is the interface between the organism and the outside world.
    The skin represents a barrier against dehydration and the penetration of undesirable elements, such as germs, allergens or toxic chemical products. When the skin is dry (xerosis) or inflamed (eczema), the role it plays as a barrier is defective.

  • Epidermal barrier


    The term epidermal barrier describes the skin's fundamental role: to separate the inside of the body from everything else that is outside, to maintain hydration and prevent the entry of micro-organisms or toxic substances. 
    This barrier function is primarily carried out by the stratum corneum, of cornified layer, which is the uppermost layer of the epidermis
    In atopic dermatitis, the barrier function is abnormal. This results in dehydration of the skin, and a vulnerability to penetration by bacteria and allergens.
    Emollients (moisturizing creams) aim to reinforce the barrier function.
  • Epidermal hyperplasia


    A histological term describing increased thickness of the skin. This is often seen in atopic dermatitis
  • Epidermal lipids


    Epidermal lipids are an important part of the stratum corneum. They can be compared to cement that surrounds the "bricks" of the cells, or corneocytes. Epidermal lipids are made of sterols, fatty acids and ceramides. They maintain the integrity of the stratum corneum, and thus the barrier function. When these lipids are altered, the role of the epidermis is compromised, and only emollient treatments can repair this. In atopic dermatitis modification to epidermal lipids plays a major role, alongside protein anomalies such as filaggrin deficiency, however, little is known about it.  
  • Epidermis


    The outside layer of the skin. The epidermis is typified by a gradual differentiation of cells which become flattened and dehydrated. These cells, called corneocytes, make up the stratum corneum, which creates the solid structure of the epidermis and plays the role of barrier or interface with the outside world.
    In atopic dermatitis, there are a number of epidermal abnormalities which are thought to be the cause of the condition.  
  • Erythema

    Skin redness.

  • Erythema


    A medical term meaning "redness".
  • Erythroderma


    A serious skin condition, where the skin is entirely red and inflamed. There are many causes of erythroderma: atopic dermatitis, psoriasis, lymphoma, drug reactions and genetic conditions. Erythroderma is prone to complications (infection, dehydration, etc.) and generally requires treatment in hospital. 
  • Essential fatty acids


    Fatty acids are simple lipids that play a part in several metabolisms and are also part of the structure of cell membranes. Some of them are deemed essential because the body is not able to synthesize them; they must therefore be obtained through diet.
    The epidermis manufactures complex lipids (ceramides) that contain essential fatty acids. Abnormalities in these lipids have been observed in cases of atopic dermatitis, and it is thought that this could be corrected by providing these essential fatty acids either by topical or oral treatment. 
    However, attempts to improve AD using oils containing essential fatty acids (evening primrose oil, borage oil, etc.), particularly those containing omega-6 such as linoleic acid, gave disappointing results. 


    An acronym: European Task Force on Atopic Dermatitis.  A group of specialists who developed the SCORAD (see also: Task Force).
  • European task force


    An international group of atopic dermatitis specialists, who have met regularly for around 20 years. Most notably, they developed the SCORAD. In English, the group is known as the ETFAD: The European Task Force on Atopic Dermatitis.
  • Exclusion diet


    A diet that is altered so that it does not contain (excludes) a type of food that the subject reacts badly to. For example, those allergic to gluten follow a gluten-free diet. Exclusion diets should be followed on the advice of, and under supervision by a doctor. The diet should maintain the necessary nutritional qualities the body needs. Exclusion diets can otherwise cause excessive and unnecessary nutritional deficiencies. 
  • Exclusion diet test


    A test consisting in removing one type of food from the diet, to see whether this will improve a condition. In general, this is followed by a reintroduction (or provocation) test, to find out whether re-including this food type triggers symptoms again. These tests are rarely used in atopic dermatitis cases, and are hard to interpret.  
  • Excoriation


    A superficial skin wound, generally due to violent scratching. It can be liable to infection
    Excoriation is one of the complications of the itching that is part of atopic dermatitis
  • Excoriation

    A scratch or abrasion.

  • Extrinsic


    From the outside. Some researchers have attempted to distinguish between extrinsic atopic dermatitis (caused by allergies) and intrinsic atopic dermatitis (with no allergic cause). This distinction has no practical impact.