• Bronchiolitis is a viral respiratory tract infection in children typically under 1 year of age
  • Respiratory syncytial virus (RSV) is the most common cause although other viruses are well recognised
  • Initial symptoms of coryza are followed after 1-2 days with cough, increased work of breathing, and difficulty feeding
  • The illness typically peaks at days 1-3 after onset of increased work of breathing and begins to improve after day 3
  • Cough and/or wheeze may persist for several weeks

Key points

  • Bronchiolitis is a clinical diagnosis. Blood tests and chest x-rays are generally not required
  • Treatment is supportive, focussed on maintaining adequate oxygenation and nutrition
  • No therapies have shown clinical benefit including salbutamol, ipratropium bromide, saline nebules and steroids
  • Pyrexic (≥38°C) infants <2 months of age may have a serious bacterial infection


Content by Dr Emma Fauteux, Dr Rory O' Brien. Last review Dr IOS 16/04/22.