*2.6. Determination of sIgE*

Serum IgE was quantified with Polycheck test (BioCheck GmbH, Leipzig, Germany) according to the manufacturer's protocol. The detection limit was assessed as 0.35 kU/l. The patient was regarded as sensitized if specific IgE (sIgE) concentration exceeded the detection limit. Main food allergens (cow's milk, hen's egg, peanuts, soybean, wheat, hazelnut, codfish) and inhalant ones (house dust mites *Dermatophagoides pteronyssinus* and *D. farinae*, cat dander, dog dander, birch, hazel, and grass pollen, olive and Alternaria spores) were tested.
