Methods: Fifty eight patients at the age above 16 were included in the study. Patients were divided into two groups. Patients included in the first group were birch allergic without any symptoms after eating food (23 persons). Patients in the other group had birch pollen allergy and they had reported clinical symptoms after eating foods such as: apple, celery, carrot, tomato, banana, peach, peanut and hazelnut. (35 persons). The skin prick tests with pollen and food allergens (commercial and native) and serum IgE concentration ( total and specific) were determined for all individuals. The immunoblotting was performed for the patients with the positive value of birch, apple, celery and/or carrot specific IgE to confirm the cross-reactivity.
Results: Patients with pollinosis and symptoms after eating plant foods were characterized by a significantly larger percentage of positive skin tests with the hazel allergen. In the first group patients revealed positive results of skin tests with food allergens, although they didn't reported the problem after consumption of them. No difference in total IgE levels was found between the two groups (271,5+/-403,8 IU/ml vs 242,5+/-340,9 IU/ml). Patients with birch allergy and hypersensitivity to food allergens showed significantly higher birch pollen specific IgE levels (11,8 +/- 14,1 IU/ml vs 4,1 +/- 6,6 IU/ml).
Conclusions: 60 % of all the patients with birch pollinosis reported manifestations symptoms after eating certain kind of food. These patients had most often clinical symptoms after eating apples, hazelnuts and of peaches, and less frequently symptoms after eating carrots, celery, peanuts, tomatoes and bananas. Although it seems that false positive results of skin tests with food allergens in the control group and the high level of the birch specific IgE might be the predictive factor of the allergy which may develop later ,they require further studies.