Clinical Research Directory

Inclusion Criteria: * informed consent by parents (and by children if age \> 8 years) * age 6 months to 18 years * term delivery (≥ 37 weeks) * active/passive understanding of German * age 6 months - \< 6 years: preschool wheeze (more than two episodes of wheeze during 12 months prior to inclusion) * age at least 6 years: doctor diagnosed asthma (according to current guidelines) Exclusion Criteria: * known inborn or perinatal pulmonary disease * airway malformation * oxygen therapy after birth with a duration of more than 24 hours * ventilator support or mechanical ventilation after birth * diagnoses of cystic fibrosis; primary ciliary dyskinesia * heart failure diagnosed after birth affecting pulmonary circulation * major respiratory diseases such as e.g. interstitial lung disease * any current non-atopic comorbidity * fever of at least 38.5°C during the last two weeks prior to the planned first visit