Can pulmonary embolism (PE) cause a dry cough?

Pulmonary Embolism and Dry Cough

Yes, pulmonary embolism (PE) can cause dry cough, and cough develops in nearly half of patients with documented PE, occasionally being the presenting complaint. 1

Relationship Between PE and Cough

Pulmonary embolism can present with a variety of symptoms, including:

• Dry cough (non-productive)
• Dyspnea (shortness of breath)
• Chest pain (particularly pleuritic)
• Tachycardia
• Tachypnea
• Syncope
• Hypoxemia

Evidence for Cough as a PE Symptom

According to the ACCP evidence-based clinical practice guidelines, cough is among the uncommon causes of PE but is still a recognized symptom 1. The guidelines specifically note that "it is not often appreciated that cough develops in nearly half of the patients with documented pulmonary embolism and that cough can occasionally be the presenting complaint."

Recent research has documented cases where troublesome cough was the sole manifestation of pulmonary embolism, particularly in patients with no other risk factors for PE 2. This highlights the importance of considering PE in the differential diagnosis when evaluating patients with persistent dry cough that doesn't respond to standard treatments.

Diagnostic Considerations

When evaluating a patient with dry cough where PE is suspected:

1. Consider PE if the following are present:

   • History of DVT or previous PE
   • Immobilization in past 4 weeks
   • Malignant disease 1
   • Cough unresponsive to inhaler treatment
   • Positive D-dimer test with normal chest X-ray 2

2. Warning signs that increase suspicion:

   • Cough accompanied by dyspnea, tachypnea, or pleuritic chest pain
   • Symptoms of DVT in the legs
   • Risk factors for thromboembolism
   • Failure to respond to standard treatments for common causes of cough

Diagnostic Algorithm for Suspected PE with Cough

1. Initial evaluation:

   • Assess for risk factors (immobilization, malignancy, history of DVT/PE)
   • Check vital signs (tachycardia, tachypnea, hypoxemia)
   • Evaluate for signs of DVT

2. Laboratory testing:

   • D-dimer testing (high sensitivity to rule out PE)
   • CBC, PT, aPTT
   • Liver and kidney function tests
   • N-terminal prohormone B-type natriuretic peptide 1

3. Imaging:

   • CT pulmonary angiography (preferred initial diagnostic test)
   • Ventilation-perfusion scan (if CTA is contraindicated)
   • Consider echocardiography to assess for right ventricular dysfunction 1

Clinical Pitfalls and Caveats

1. Misdiagnosis risk:

   • Dry cough from PE can be misattributed to more common conditions like asthma, bronchitis, or respiratory infections 3
   • Case reports document patients with PE-induced cough being misdiagnosed with asthma exacerbations 3

2. Delayed diagnosis:

   • Cough as the sole symptom may delay diagnosis as clinicians pursue more common causes first
   • PE should be considered when cough persists despite appropriate treatment for common causes 2

3. Atypical presentations:

   • PE can present with isolated cough without the classic triad of dyspnea, chest pain, and hemoptysis
   • Non-thrombotic PE (tumor emboli, fat emboli, etc.) may also present with cough 1

Treatment Implications

When PE is diagnosed in a patient presenting with dry cough:

• Initiate anticoagulation therapy promptly
• Consider thrombolytic therapy in high-risk cases
• Monitor for resolution of symptoms, including cough
• Evaluate for underlying causes of thromboembolism

In summary, while dry cough is not the most common presenting symptom of PE, it is a recognized manifestation that clinicians should be aware of, particularly when the cough is persistent and unresponsive to standard treatments for more common causes.