Birch pollen-related foods can cause late eczematous reactions in patients with atopic dermatitis.

ABSTRACT

BACKGROUND: Previous studies have indicated that in patients with atopic dermatitis (AD) and birch pollen allergy pollen-related foods are able to cause late eczematous response. However, the relevance of AD worsening by ingestion of birch pollen-related foods is still a matter of debate. OBJECTIVE: The purpose of this retrospective study was to determine how frequently birch pollen-related foods induce a deterioration of eczema. Additionally, the diagnostic value of specific IgE (sIgE) determination was evaluated. METHODS: A total of 182 children and adults with AD and suspected birch pollen-related food allergy underwent 261 double-blind placebo-controlled food challenges (DBPCFC). Total and sIgE levels were determined prior to DBPCFC. RESULTS: Sixty-five patients developed allergic reactions (responders) upon DBPCFC with birch pollen-related foods (n = 103 DBPCFC). Of these, 32 patients exhibited significant deterioration of AD defined as a median increase of 15.4 severity scoring of atopic dermatitis index points (95% CI 12.4-16.3) from baseline making up 37% of all positive reactions. Responders showed significantly higher sIgE levels to birch pollen and apple as well as a higher prevalence of allergic rhinoconjunctivitis compared to nonresponders (P < .05). However, patients with late eczematous response could not be differentiated from those with isolated immediate-type reactions by sIgE levels. CONCLUSION: In a subpopulation of patients with AD and birch pollen sensitization, related foods should be considered as a trigger for an aggravation of eczema. As sufficient markers for prediction of late eczematous reactions are still lacking, DBPCFC cannot be replaced in diagnosis of birch pollen-related foods in patients with AD. CLINICAL IMPLICATIONS In patients with AD and birch pollen allergy, birch pollen-related foods should be considered as a provocation factor for an aggravation of disease signs and symptoms.