17th February 2025

Asthma differential diagnosis

It is important to be aware of other differentials that may present with similar symptoms to asthma, such as wheezing, cough and shortness of breath:

• COPD: consider in older patients with a strong smoking history. Typically of chronic onset, with sputum production and more frequent respiratory tract infections. Be aware of asthma-COPD-overlap syndrome, where patients may have elements of both COPD and asthma.
• Heart failure: patients can present with wheeze, cough and breathlessness; assess for evidence of fluid overload.
• Angioedema: could be secondary to an allergic reaction, hereditary angioedema or ACE-inhibitor related. Swelling in the connective tissue around the airways can cause wheeze and breathlessness.
• Eosinophilic granulomatosis with polyangiitis (EGPA): a small-medium vessel vasculitis that can commonly affect the lungs, skin and nerves, and is associated with eosinophilia and p-ANCA (usually anti-MPO antibodies). Adult-onset asthma is one of the most common signs of EGPA and it typically does not respond well to standard asthma treatment.
• Inhalation of a foreign body: typically sudden-onset wheeze and breathlessness following a history of inhaling or aspirating a foreign body.

References

• British guideline on the management of asthma. A national clinical guideline [Internet]. 2003 [cited 2022 Jan 31] Available from: https://www.brit-thoracic.org.uk/document-library/guidelines/asthma/btssign-guideline-for-the-management-of-asthma-2019/ 
• National Institute for Health and Care Excellence. Asthma: diagnosis, monitoring and chronic asthma management [Internet]. 2017 [cited 2022 Jan 31]  Available from: https://www.nice.org.uk/guidance/ng80/resources/asthma-diagnosis-monitoring-and-chronic-asthma-management-pdf-1837687975621 
• Chapman S. Oxford handbook of respiratory medicine. Oxford, United Kingdom: Oxford University Press; 2014