Birch pollen-related food as a provocation factor of allergic symptoms in children with atopic eczema/dermatitis syndrome.

BACKGROUND: Food allergy to cow's milk or hen's egg is a common problem in children with atopic eczema/dermatitis syndrome (AEDS) but the role of birch pollen-related food for the induction of allergic symptoms is still not clear. PATIENTS/METHODS: Twelve children (median age 5 years) with AEDS underwent an oral challenge with those birch pollen-related foods which were reported to induce no immediate symptoms, but were consumed on a regular basis. Total IgE and specific IgE to birch pollen, Bet v 1/2 and various birch pollen-related foods were determined. RESULTS: Seven of 12 children showed immediate and/or late eczematous reactions upon ingestion of birch pollen-related foodstuff. Four children showed a worsening of eczema 24 h upon oral challenge with a significant difference in SCORAD before and after challenge. There were no differences in terms of total IgE or birch pollen-specific IgE between children with a late eczematous response and non-reacting children. CONCLUSIONS: Birch pollen-related food may induce allergic symptoms in children with AEDS who exhibit a sensitization to birch pollen. Oral challenge tests should be performed in those children who suffer from severe AEDS and who are highly sensitized to birch pollen allergens even in the absence of a history suggestive of food allergy.

Late eczematous reactions to food in children with atopic dermatitis.

BACKGROUND: Food allergy is a common problem in patients with atopic dermatitis (AD), particularly in children. While immediate reactions to food are well characterized, the importance of food as a provocation factor for late eczematous reactions has been a subject of debate for several decades. OBJECTIVE: To investigate the importance of food for the induction of late eczematous reactions in children with AD and to correlate the clinical outcome to the results of specific IgE determinations and atopy patch tests (APTs). METHODS: One hundred and six double-blind placebo-controlled food challenges (DBPCFCs) to cow's milk, hen's egg, wheat and soy in 64 children with AD (median age 2 years) were analysed retrospectively. Total and food-specific IgE were determined by CAP RAST FEIA and APTs with native foodstuff were performed. The diagnostic values of specific IgE and APT results were calculated. RESULTS: Forty-nine (46%) of the challenges were related to a clinical reaction. An exacerbation of AD (late eczematous reaction) commonly occurred 24 h after the ingestion of food. Isolated late eczematous reactions were seen in 12% of all positive challenges. Forty-five percent of the positive challenges were associated with late eczematous responses, which followed immediate-type reactions. The sensitivity of food-specific IgE and the APT was 76% and 70%, respectively. Specific IgE and APT were often false positive, which resulted in low positive predictive values (64% and 45%, respectively). CONCLUSIONS: Late eczematous reactions may often be observed upon food challenge in children with AD. Due to the poor reliability of food-specific IgE and APT results DBPCFCs have still to be regarded as the gold standard for the appropriate diagnosis of food responsive eczema in children with AD.