aUniversity Clinic Golnik, Golnik

bFaculty of Medicine, University of Ljubljana

cDepartment of Allergology, Rheumatology and Clinical Immunology, Children's Hospital, University Medical Center Ljubljana, Ljubljana, Slovenia

Correspondence to Professor Tadej Avčin, MD, PhD, Department of Allergology, Rheumatology and Clinical Immunology, Children's Hospital, University Medical Center Ljubljana, Bohoričeva 20, SI-1525 Ljubljana, Slovenia. Tel: +386 1 522 9642; e-mail: [email protected]