Wheezing in childhood: incidence, longitudinal patterns and factors predicting persistence.

Childhood asthma is frequently perceived as a disease with uniform clinical pathways. This perception might be an oversimplification. The aim of the present study was to investigate the incidence and natural course of wheeze over the first 13 yrs of life and analyse the risk factors predicting wheeze at 11-13 yrs of age. The Multicentre Allergy Study, a German birth cohort, recruited 1,314 children in 1990. Physical examinations, interviews on atopic diseases, immunoglobulin (Ig)E and lung function tests were performed up to 13 yrs of age. Complete data on the course of wheeze were available for 441 children. It was found that incidence of wheezing declined with age. The first wheezing episode was reported by 29, 9 and 9% of participants at < or = 3 (early wheezers), 3-6 (late wheezers), and > 6 yrs (very late wheezers) of age, respectively. Wheezing at the age of 13 yrs was associated with parental atopy, and with IgE sensitisation to common allergens, elevated total IgE and exposure to high levels of indoor allergens in early life. All these associations were remarkably stronger among early wheezers than among early nonwheezers. In conclusion, the relevance of an early expression of atopy as a predictor of wheezing at age 13 yrs declines with increasing age of wheezing onset.