Department of Dermatology and Allergology Biederstein, School of Medicine, Technical University of Munich, Biedersteiner Strasse 29, D-80802 Munich, Germany. Department of Paediatrics, Paediatric Gastroenterology, Allergology and Nutrition, Medical University of Gdańsk, 80803 Gdańsk, Poland. Department of Dermatology, Venereology and Allergology, Medical University of Gdańsk, 80210 Gdansk, Poland. Department of Allergology, Medical University of Gdańsk, 80210 Gdansk, Poland. Department of Internal Medicine I, Division of Hematology & Hemostaseology, Medical University of Vienna, 1090 Vienna, Austria. Ludwig Boltzmann Institute for Hematology and Oncology, Medical University of Vienna, 1090 Vienna, Austria.