1. Dermatology Clinic, School of Medicine, Ss. Cyril and Methodius University, Skopje, Republic of Macedonia;
2. University Clinic of Respiratory and Allergic Diseases Golnik, Golnik, Slovenia;
3. Medical Faculty, Ljubljana, Slovenia;
4. Clinic of Allergology and Immunology, Clinical Center of Serbia, Belgrade, Serbia;
5. General Hospital Šibenik, Šibenik, Croatia