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10th January 2024
Differential Diagnosis
The differential diagnosis of pneumothorax is wide and relates to any condition that can present with acute-onset chest pain and dyspnoea. Clinical history and examination findings are key to establishing the underlying diagnosis, as many cardiac and respiratory conditions can present similarly. The table below summaries some common differential diagnoses of this presentation to be aware of.
| Diagnosis | Clinical History Points | Clinical Examination Findings |
|---|---|---|
| Respiratory | ||
| Pulmonary Embolism | VTE risk factor identified: active malignancy, combined oral contraceptive pill, recent travel >4 hours or surgery.
Pleuritic chest pain. Haemoptysis associated. |
Clinical examination in PE is typically normal in uncomplicated PE.
In large PE – signs of right heart failure may be present: peripheral oedema, raised JVP, pulsatile hepatomegaly. Chest x-ray: normal. |
| Acute asthma exacerbation | Acute shortness of breath + wheeze.
Increased use of PRN salbutamol inhaler. Cough +- sputum production +- fever. Trigger prior to onset. |
Bilateral wheeze.
Often young patient demographic. Chest x-ray: normal, or consolidation if infective exacerbation. |
| Acute COPD exacerbation | Acute shortness of breath.
Wheeze +- cough +- sputum production history. Not associated with chest pain typically. |
Bilateral wheeze.
Prolonged expiratory phase +- tar staining. Type 2 respiratory failure in some cases. Chest x-ray: hyper-inflated lung fields, flattened hemidiaphragms. |
| Cardiac | ||
| Acute myocardial infarction | Crushing, central chest pain.
Sweating, nausea/ vomiting and dizziness associated. Other cardiac risk factors: type 2 diabetes, smoking, alcohol, increased BMI. |
In acute myocardial infarction – grey, sweaty appearance.
Respiratory examination normal. Raised BMI, tar staining may be noted. Chest x-ray: normal or acute pulmonary oedema. |
| Aortic dissection | ‘Tearing’ central chest pain through to the back.
Pre-syncopal/ syncopal episode. |
Difference in blood pressure between 2 arms.
Radial-radial delay. Acute aortic regurgitation (early diastolic murmur) Chest x-ray: mediastinal widening. |
| Acute pulmonary oedema | Cough with pink frothy sputum
Progressive dyspnoea followed by sudden onset nature. Orthopnoea and paroxysmal nocturnal dyspnoea. |
Respiratory distress
Bilateral crackles throughout both lung fields. +- signs of right heart failure. Chest x-ray: bilateral pleural effusions, pulmonary congestion. |
Table 5: Differential diagnosis of pneumothorax with key history and clinical examination characteristics.
Table adapted from –
Gary Lee Y. Clinical presentation and diagnosis of pneumothorax [Internet]. UpToDate. 2021 [cited 2022 Jun 1]. Available from: https://www.uptodate.com/contents/clinical-presentation-and-diagnosis-of-pneumothorax?search=pneumothorax &source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2#H3647761918
UpToDate. Evaluation of the adult with chest pain in the emergency department [Internet]. 2022 [cited 2022 Jun 1]. Available from: https://www.uptodate.com/contents/evaluation-of-the-adult-with-chest-pain-in-the-emergency-department?search=chest pain&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3#H18
UpToDate. Evaluation of the adult with dyspnea in the emergency department [Internet]. [cited 2022 Jun 1]. Available from: https://www.uptodate.com/contents/evaluation-of-the-adult-with-dyspnea-in-the-emergency-department?search=shortness of breath&source=search_result&selectedTitle=2~150&usage_type=default&display_rank=2#H4
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