Stability and predictiveness of multiple trigger and episodic viral wheeze in preschoolers

BACKGROUND: In 2008, the European Respiratory Society Task Force proposed the terms multiple-trigger wheeze (MTW) and episodic (viral) wheeze (EVW) for children with wheezing episodes. We determined MTW and EVW prevalence, their 24-month stability and predictiveness for asthma. METHODS: In total, 565 preschoolers (1-, 2- and 3-year-olds) in primary care with respiratory symptoms were followed until the age of 6 years when asthma was diagnosed. MTW status and EVW status were determined using questionnaire data collected at baseline and after one and 2 years. We distinguished 3 phenotypes and determined their 24-month stability, also accounting for treatment with inhaled corticosteroids (ICS). Logistic regression was used to analyse the phenotypes' associations with asthma. RESULTS: Two hundred and eighty-one children had complete information. MTW and EVW were stable in 10 of 281 (3.6%) and 24 of 281 (8.5%), respectively. The odds of developing asthma for children with stable MTW and stable EVW were 14.4 (1.7-119) and 3.6 (1.2-11.3) times greater than those for children free of wheeze (for at least 1 year). ICS was associated with increased stability of MTW and EVW. CONCLUSIONS: Stable multiple-trigger and stable episodic viral wheeze are relatively uncommon. However, 1- to 3-year-olds with stable MTW are at much increased risk of asthma.