<s>[INST] context: A ie Scabies The diagnosis is scabies, which is characterized by severe itching and diffusely scattered papular and papulo-vesicular lesions which may appear on all pas of body except the face. It is common to find other individuals especially children staying in same house also showing similar features. In infants, eczematization is very common and it leads to exudation and crusting especially on the wrist and ankle. Secondary infection leads to pustule, crust fever and lymphadenopathy. Involvement of palm & soles, duration of < 6 weeks (2 weeks) and presence of same lesions in mother, our the diagnosis of scabies. Scabies Intense itching even in presence of minor physical signs The physical sign are essentially those of eczema & effects of scratching. Vesicles are seen but excoriations and prurigo-like papules are more common. Pathognomic lesion is burrow or run (in stratum corneum); which is a tiny, raised, linear or serpiginous white mark. The best sites to find burrows are palms & interdigital areas of fingers, flexural creases and over the elbows. Other common sites of involvement are - anterior axillary fold, buttock fold, areola of breast, lower abdomen, genitalia, knees, ankle and soles. Head and neck is involved in infants only. Same type of lesion may also present in family members. Positive family or social history Finding of mite or egg by pin or by examining skin scrapings or a skin surface biopsy taken with cynoacrylate glue, confirms diagnosis. Atopic Dermatitis/Infantile Extremely itchy Q, erythematous papular or papulo-vesicular lesions mostly on face and flexures (popliteal fossa, antecubital fossae & wrist) of infant, children, adolescent & young adult * Itching made worse by change in temperature, sundry (rainy season) etc. * Perpetual rubbing & scratiching I/ t excoriation, lichenification, hyperlinear palms & Denny morgan fold (crease lines just below eyes) . * Personal or family h/O of atopy (eg asthama, hay fever, rhinitis, uicariaQ) present Clinical course lasting longer than 6 weeksQ Course marked by exacerbation & remission May be associated with alopecia areate & susceptibility to skin infection Seborrheic Dermatitis Infantile S.D. may be evident within first few weeks of life (usually < 3 months)Q. It involves scalp (cradle cap), face or groin. It is rarely seen in children beyond infancy but becomes evident again during adult life. Lesions are characterized by greasy scales overlying erythematous patches or plaques Reddened itchy patches may become either scaly or crusted & exudative. The most common location is scalp where it may be recognized as severe dandruff Other sites are eyebrows, eyelids, glabella, and nasolabial folds. Scaling of external auditory canal is common & mistaken as fungal infection. Retroauricular areas often become macerated & tender. May be associated with Parkinson's disease, cerbro-vascular accident & HIV infection. Rarely groin, axilla central chest, sub mammary folds & gluteal cleft may also be involved. Impetigo contagiosa Contagious superficial skin infection caused by staph. aureus (mostly) Red, sore areas, which may blister, appear on exposed skin Yellowish gold curst surmounts the lesion It is mostly a disorder of prepubeal children May be associated with glomeruloneprhitis, [/INST] question: A 6 month old infant presented with multiple erythematous papules & exudative lesions on the face, scalp, trunk and few vesicles on palms and soles for 2 weeks. His mother has H/o itchy lesions. The most likely diag is: | options: A: Scabies B: Infantile exzema (atopic dermatitis) C: Infantile sebornheic dermatitis D: Impetigo contagiosa | answer: A </s>