Recognizing that respiratory syncytial virus (RSV)- and RV-induced bronchiolitis are both associated with an elevated risk for asthma, investigators explored whether RSV or RV types are differentially linked to the future use of asthma control medications. During the winter seasons of 2008 to 2010, they enrolled a total of 408 Finnish children who had been hospitalized for bronchiolitis at <24 months of age. Virus detection was performed with the use of real-time reverse transcription polymerase chain reaction from nasal wash swabs. Then, 4 years later, the researchers studied the patients’ current use of asthma control medications.

Overall, 349 children completed the study. The median participant age at study entry was 7.5 months. A total of 42% of the children had RSV, 29% had RV, 2% had both RSV and RV, and 27% had a non-RSV/-RV etiology. Study results demonstrated that the participants with RV-A (adjusted hazard ratio [aHR], 2.30; P =.01), RV-C (aHR, 3.48; <.001), and non-RSV/-RV (aHR, 1.99; =.004) began their asthma control medication earlier than patients with RSV bronchiolitis.

At 4 years, 27% of the patients were using asthma control medication. Both an RV-A etiology (adjusted odds ratio [aOR], 3.02; P =.03) and an RV-C etiology (aOR, 3.72; P <.001) were significantly associated with the current use of asthma medications. In fact, the highest risk was reported among children with RV-C and a history of atopic dermatitis and fever at the time of hospitalization (aOR, 5.0; P =.03).

The investigators concluded that if these study findings are confirmed in other trials, testing for the viral etiology of bronchiolitis should be recommended in newly revised treatment guidelines to better assess these patients’ future risk of developing asthma.


Bergroth E, Aakula M, Elenius V, et al. Rhinovirus type in severe bronchiolitis and the development of asthma [published online September 11 2019]. J Allergy Clin Immunol Pract. doi:10.1016/j.jaip.2019.08.043