Eczema, 5th MBBS, from Principles of Internal Medicine, By Adeleke

Eczema (Dermatitis) – Key Points for Exam Prep This material covers Atopic Dermatitis (AD) , Allergic Contact Dermatitis (ACD) , and Seborrheic Dermatitis (SD) . Atopic Dermatitis is a chronic, pruritic, inflammatory skin disease linked to an atopic state (often with asthma, allergic rhinitis, food allergies). It starts before age 5 in 80% of cases. Sites: face, neck, arms, legs (spares groin/axilla). Key features: pruritus, xerosis, lichenification, Dennie-Morgan folds, elevated IgE. Infantile pattern: face/extensors; childhood pattern: flexural (antecubital/popliteal). Treatment: moisturizers, topical steroids (low potency on face/groin; high potency elsewhere), topical calcineurin inhibitors (tacrolimus/pimecrolimus – no atrophy), antihistamines for pruritus, antibiotics for S. aureus. Allergic Contact Dermatitis is a type IV delayed hypersensitivity reaction. Common allergens: nickel, neomycin, poison ivy, fragrances. Presents as linear/angular pruritic papules/vesicles. Treatment: avoid allergen, high-potency topical steroids, or oral prednisolone. Seborrheic Dermatitis affects sebum-rich areas (scalp, face, chest). Caused by Malassezia. Features greasy scales on red patches. Infants: cradle cap + diaper dermatitis. Treatment: low-potency steroid + antifungal (ketoconazole).