Rhinovirus type in severe bronchiolitis and the development of asthma

Abstract Background Respiratory syncytial virus (RSV) and rhinovirus (RV) induced bronchiolitis are associated with an increased risk of asthma but more detailed information is needed on virus types. Objective To study whether RSV or RV types are differentially associated with the future use of asthma control medication. Methods Over two consecutive winter seasons (2008-2010), we enrolled 408 children hospitalized for bronchiolitis at age Results 349 (86%) children completed the 4-year follow-up. At study entry, the median age was 7.5 months, and 42% had RSV, 29% RV, 2% both RSV and RV, and 27% had non-RSV/-RV etiology. The children with RV-A (adjusted hazard ratio (aHR) 2.3; P = .01), RV-C (aHR 3.5; P Conclusion Severe bronchiolitis caused by RV-A and RV-C was associated with earlier initiation and prolonged use of asthma control medication. The risk was especially high when bronchiolitis was associated with RV-C, atopic dermatitis and fever.