Atopic dermatitis.
Atopic dermatitis is a common, chronic skin condition characterized by xerosis, pruritus, and inflammation. Numerous factors place individuals at increased risk for developing this disease. T-helper cells and their cytokines, in addition to immunoglobulin E and eosinophils, play a major role in the pathogenesis of atopic dermatitis. Various hypotheses including the "hygiene hypothesis" and the "keratinocyte apoptosis hypothesis" have been proposed. Diagnosis is based on clinical criteria rather than objective testing. Allergic reactions to several triggers including foods may exacerbate symptoms. Treatment for atopic dermatitis consists of avoidance of triggers and administration of emollients, steroids, and topical immune response modifiers such as tacrolimus. Further research is necessary to better understand this disease.