Background Viral bronchiolitis is a common lower respiratory infection during infancy. 50% of infants with acute Bronchiolitis develop Post bronchiolitis wheezing (PBW) that may cause childhood asthma. Vitamin A deficiency impairs epithelial integrity, systemic immunity and increases the severity of childhood respiratory infections such as RSV. In this study the effect of vitamin A in improving PBW has been evaluated.

Methods This was a double blind pilot trial on 84 patients aged 2 to 12 months old who were admitted in Emam Sajad Hospital in Yasuj (Iran) from October 2012 to October 2013. The patients were diagnosed by history, physical examination and chest x-ray by a paediatrician. The 84 individuals were put in case and control groups (42 in each group). The case group received 5000 IU/kg Vitamine A intramascularly, plus cold and wet oxygen, and beta 2 agonist (ventolin) by nebulizer, and the control group received the same except vitamin A.1,2 and 3 weeks after treatment the patients were examined by the same paediatrician and were compared based on severity of wheezing, and response to the treatment (decrease in wheezing, distress and cough).

Findings The diferences of demographic data and severity of wheezing were not significant between the groups before treatment. There were significant differences in response to treatment between two study groups after 1, 2 and 3 weeks following treatment (p = 0.045, p = 0.001 and p = 0.001 respectively). No side effects were seen during and after the course of treatment.

Conclusion Usual treatments together with Vitamin-e A have stronger effect on reducing post bronchiolitis wheezing, compared with usual treatments alone.