 b. Prognosis: This follow-up-study will be performed in collaboration between the principal investigator and the collaborating physicians at the local paediatric departments. The clinical follow-up visit includes a structured parental interview, application of the Oslo severity score20 for obstructive airways disease, assessment of atopic eczema and rhinitis, skin prick test as well as blood sampling for analyses including IgE and DNA for epigenetic studies see table 4 . 