Assessment of acute bronchitis

Patients with acute bronchitis often present with nonspecific symptoms of upper or lower respiratory tract infection. In addition to cough, symptoms of acute bronchitis may includeKinkade, 2016Macfarlane, 2001:

• purulent or coloured sputum (not predictive of a bacterial infection)
• dyspnoea
• wheeze
• chest discomfort or pain (caused by frequent coughing)
• nasal congestion
• headache
• fever.

The cough often lasts for up to 3 weeks and, in 90% of patients, resolves within 4 weeksNational Institute for Health and Care Excellence (NICE), 2019Thompson, 2013. However, in 10% of patients, the cough will persist for up to 8 weeks because of the time taken for bronchial inflammation to resolveKinkade, 2016Smith, 2017Thompson, 2013. Persistent cough is the main reason patients seek medical advice for acute bronchitis, reinforced by anxiety about slow recovery time.

If cough is not the predominant clinical feature, consider the likelihood of upper respiratory tract infections such as acute rhinosinusitis, acute tonsillitis and pharyngitis (see Sore throat).

Exclude more serious causes of cough, such asBraman, 2006Kinkade, 2016:

• pneumonia – consider in patients with tachypnoea at rest, tachycardia, persistent fever, rigors, hypoxaemia or crepitations (crackles) on auscultation that do not clear with coughing. See Clinical features of CAP in adults or Diagnosis of HAP.
• influenza, COVID-19 and other respiratory viruses – consider performing nose and throat or nasopharyngeal swabs for nucleic acid amplification testing (NAAT) (eg polymerase chain reaction [PCR]) to detect respiratory viruses.
• pertussis (whooping cough) – consider in patients with paroxysmal cough or recent exposure to a patient with pertussis. Older children and adults often lack the classical signs of pertussis so consider performing a posterior nasopharyngeal swab or nasopharyngeal aspirate¹; a throat swab or anterior nasal swab is less sensitive for the diagnosis of pertussis.
• asthma – consider if wheeze could represent a new diagnosis of asthma. For further information, see asthma in adults, adolescents and children 6 years and over.
• heart failure – consider if signs of oedema or weight gain are present in addition to cough.

For a summary of common or important causes of cough, see Cough in adults or Cough in children. For detailed advice on diagnosis and assessment of cough, see the Cough in Children and Adults Diagnosis and Assessment (CICADA) guidelines.

Chest X-ray is not indicated for patients with acute bronchitis. If pneumonia is suspected, consider diagnostic imaging – see Diagnostic imaging for CAP in adults or Diagnosis of HAP.