What should you know about cellular bronchiolitis?

The tiny air passages deep in the lungs can swell and fill with mucus. Air then moves less freely, which may produce a whistling sound, faster breathing or a cough. Bronchiolitis commonly follows a viral respiratory infection. Symptoms can change over several days, and feeding may become harder when a child is working harder to breathe.

A child may have cough, fever, wheezing, a blocked nose or reduced interest in feeds. [Cough](/symptoms/cough/) and [wheezing](/symptoms/wheezing/) can occur together, but the severity of breathing effort matters more than the sound alone.

Offer frequent small feeds and fluids if the child can swallow comfortably. Keep the child upright while awake, clear nasal mucus gently, and avoid tobacco smoke. Check breathing, alertness and wet nappies regularly. Do not give antibiotics or cough medicines unless a clinician has prescribed them; viral bronchiolitis does not improve with antibiotics.

A clinician may assess oxygen levels, breathing effort and hydration during a [Child Health Consultation](/treatments/consultations-and-assessment/child-health-consultation/). Some children need oxygen, fluids or monitored support; a [Nebuliser Treatment](/treatments/acute-and-urgent-care/nebuliser-treatment/) is not suitable for every child.

Seek urgent medical help if the child is struggling to breathe, the skin between the ribs pulls in, lips look blue or grey, pauses in breathing occur, or the child is unusually floppy or difficult to wake. Arrange prompt assessment if feeds are markedly reduced, wet nappies are much less frequent, or fever persists with worsening breathing. [Fever](/symptoms/fever/) alone does not show how severe the airway problem is.

Ask: How hard is the child working to breathe? Are oxygen levels and hydration reassuring? Which signs mean we should return urgently? How can feeds be offered safely, and when should follow-up occur?