assessment and clinical diagnosis

Last edited 08/2021 and last reviewed 08/2021

When diagnosing bronchiolitis, take into account that it occurs in children under 2 years of age and most commonly in the first year of life, peaking between 3 and 6 months

  • symptoms usually peak between 3 and 5 days, and that cough resolves in 90% of infants within 3 weeks

NICE state that a diagnosis of bronchiolitis can be made if the child has a coryzal prodrome lasting 1 to 3 days, followed by:

  • persistent cough and either tachypnoea or chest recession (or both)
  • and either wheeze or crackles on chest auscultation (or both)

Following symptoms are common in children with this disease:

  • fever (in around 30% of cases, usually of less than 39°C)
  • poor feeding (typically after 3 to 5 days of illness)

Young infants with this disease (in particular those under 6 weeks of age) may present with apnoea without other clinical signs

A diagnosis of pneumonia should be considered if the child has:

  • high fever (over 39°C)
  • and/or persistently focal crackles

Consider a diagnosis of viral-induced wheeze or early-onset asthma rather than bronchiolitis in older infants and young children if they have:

    • persistent wheeze without crackles or
    • recurrent episodic wheeze or a personal or
    • family history of atopy
  • these conditions are unusual in children under 1 year of age