Allergic rhinitis
Allergic rhinitis was diagnosed at the COPSAC research unit at age 7 and 12 years based on a parental interview on history of symptoms. Allergic rhinitis was defined as substantial and reoccurring sneezing, blocked, itchy or runny nose severely affecting the wellbeing of the child in the past 12 months in periods without accompanying common cold or flu, and with congruence between symptoms, relevant exposure and aeroallergen sensitization (positive sIgE and/or skin prick test)19–22.
Filaggrin mutationGenotyping for common loss-of-function mutations in FLG , R501X, 2282del4, R2447X and S3247X was performed as previously described.2 A FLG mutation carrier was defined as having at least one gene mutation.