Original Paper Severe bronchiolitis in infants under six months is a major risk factor for recurrent wheezing

La bronquiolitis grave en lactantes menores de seis meses es un factor de riesgo para las sibilancias recurrentes Background: several individual and epidemiological risk factors have been associated with recurrent wheezing after acute bronchiolitis (AB). Few research studies focus on very young infants under six months old. Objectives: to find what risk factors are associated with recurrent wheezing in young infants (<6 month-old) hospitalized with moderate to severe acute bronchiolitis (AB) at our setting. Material and methods: a prospective-retrospective, observational study was designed and carried out from January 2009 to December 2011 in a secondary care hospital. Eighty previously healthy patients aged 7-180 days, hospitalized with a first episode of acute moderate AB, were studied. Results: the mean age of infants was 69±42 (range 7-180) days. Crude analysis of relative risk (RR) for recurrent wheezing showed an increased RR in males (p=0.05, RR=1.7 CI 95%: 0.9-3.1), patients in daycare (p=0.03, RR=1.9 CI 95%: 1.1-3.3), with elder siblings (p=0.03, RR=2.2 CI 95%: 0.9-5.1), high-flow therapy (p=0.05, RR=2.1 CI 95%: 1.3-3.6), critical care ( p=0.01, RR=2.5 CI 95%: 1.6-3.8), and mechanical ventilation (p=0.05, RR=2.7 CI 95%: 2.0-3.7). After multivariate analysis, daycare attention (OR: 6.06, CI 95%: 1.4-25; p=0.013) and having elder siblings (OR: 4.1, CI 95% 1.1-14.5, p=0.029) were found to be independent risk factors for recurrent wheezing. Conclusions: daycare attendance and having elder siblings were independently associated with recur- rent wheezing. We suggest that severity of bronchiolitis (needing PICU, high flow therapy and me - chanical ventilation) is a remarkable risk factor for recurrent wheezing one year after AB.