Evaluation of food allergy in patients with atopic dermatitis.

Atopic dermatitis (AD) is a common skin disease characterized by inflammatory, chronically relapsing and pruritic eczematous flares. Its estimated incidence is 10% to 30% in children. Food allergy has been well documented in approximately one-third of children with a moderate-to-severe AD. Cow's milk, hen's egg, peanut, wheat, soy, nuts, and fish are responsible for >90% of food allergy in children with AD. The incidence and type of food can vary with age. In infants, cow's milk, hen's egg, peanut, and soy and, in older children, wheat, fish, tree nuts, and shellfish are the most common food allergens. Birch-associated foods have also been described as potential triggers of AD in children as well as in adults. The diagnosis of food allergy in AD is currently based on the clinical history, skin prick tests, or blood test screening, followed by an elimination diet and/or standardized oral food challenge. Once an underlying food allergy is confirmed, the avoidance of the incriminated food is generally recommended and usually leads to an improvement of the AD. Follow-up clinical evaluation with a detailed history and tracking of the level of specific IgE to implicated foods are typically used to evaluate the development of clinical tolerance, further confirmed by an oral food challenge.