PREVALENCE OF IGE-MEDIATED FOOD ALLERGY AMONG CHILDREN WITH ATOPIC-DERMATITIS

Objective. There is a growing body of clinical and laboratory evidence to support the notion that food allergy plays a role in the pathogene sis of atopic dermatitis (AD). However, the incidence of IgE-mediated food allergy in children with AD is not well established. Design. A pr ospective study to determine the prevalence of IgE-mediated food hyper sensitivity among patients referred to a university-based dermatologis t for evaluation of AD. Setting. University hospital pediatric dermato logy clinic. Patients. A total of 63 patients with AD were recruited ( 35 male; 32 white, 24 African-American, 7 Asian). Methods. Patients we re assigned an AD symptom score (SCORAD) and were screened for food-sp ecific serum IgE antibodies to six foods (milk, egg, wheat, soy, peanu t, fish) known to be the most allergenic in children. The levels of fo od-specific serum IgE were determined by the CAP System fluoroscein-en zyme immunoassay (CAP); patients with a value greater than or equal to 0.7 kIUa/L were invited for an additional allergy evaluation. Those w ith CAP values below the cutoff were considered not food allergic. Pat ients were considered to be allergic if they met one of the following criteria for at least one food: 1) reaction on food challenge; 2) CAP value more than the 95% confidence interval predictive for a reaction; 3) convincing history of an acute significant (hives, respiratory sym ptoms) reaction after the isolated ingestion of a food to which there was a positive CAP or prick skin test. Results. A total of 63 patients (median age, 2.8 years; median SCORAD, 41.1) were recruited; 22 had n egative CAP values (without a significant difference in age or SCORAD score, compared with the 41 with positive specific IgE values). Furthe r allergy evaluation was offered to the 41 remaining patients; 10 were lost to follow-up and 31 were evaluated further. Of these, 19 underwe nt a total of 50 food challenges (36 double-blind, placebo-controlled, and 14 open), with 11 patients experiencing 18 positive challenges (9 4% with skin reactions). Additionally, 6 patients had a convincing his tory with a predictive level of IgE; 5 had a convincing history with p ositive, indeterminate levels of IgE; and 1 had predictive levels of I gE (to egg and peanut) without a history of an acute reaction. Overall , 23/63 (37%; 95% confidence interval, 25% to 50%) had clinically sign ificant IgE-mediated food hypersensitivity without a significant diffe rence in age or symptom score between those with or without food aller gy.Conclusions. Approximately one third of children with refractory, m oderate-severe AD have IgE-mediated clinical reactivity to food protei ns. The prevalence of food allergy in this population is significantly higher than that in the general population, and an evaluation for foo d allergy should be considered in these patients.