Atopic and seborrheic dermatitis: practical management.
Atopic dermatitis is common and causes sleep loss, a disfiguring appearance, an unpleasant odour, teasing, short stature and restriction of career choice in severe cases. There are no drugs which control the scratching; distraction, keeping the nails short and smooth, and the use of mittens at night are all helpful. The sedative action of the older H1 antihistamines makes them useful if scratching prevents a child from falling asleep. Emollients are useful for the associated skin dryness. The least potent topical steroids should be used sparingly to avoid the main hazards of skin atrophy, systemic absorption and growth stunting. Bacterial skin infection with Staphylococcus aureus and sometimes beta-haemolytic streptococci is common and is best treated with oral antibiotics. Herpes simplex virus skin infection is also common; the initial infection occasionally causes a lethal (if untreated) illness. Allergy to house dust mites, pet animals, pollen and food can worsen dermatitis in some cases. There is no test however, which can be used to predict those patients who will respond to avoidance measures, so that management tends to be based on empirical trials of antigen avoidance. Seborrheic dermatitis is a common disorder that usually occurs in the first months of infancy. Findings consist of greasy yellow scales on the scalp (most simply treated with an emollient) and well-demarcated erythematous patches in the diaper area that spread to other areas such as the axillae and neck (usually requiring topical steroids). Some cases go on to develop atopic dermatitis, but many others, although florid, resolve spontaneously.