1. Department of Pediatric and Adolescent Medicine Herlev and Gentofte Hospital University of Copenhagen Copenhagen Denmark
2. Primary Care Health Clinic Oxie Region Skåne Oxie Sweden
3. Allergy Clinic Herlev and Gentofte Hospital University of Copenhagen Copenhagen Denmark
4. COPSAC Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital University of Copenhagen Copenhagen Denmark