Differential Diagnosis for a Non-Productive Cough

Given the symptom of a non-productive cough, the differential diagnosis can be organized into the following categories:

• Single Most Likely Diagnosis
  • Acute Bronchitis: This is often the most common cause of a non-productive cough, especially if the patient has recently had a viral upper respiratory infection. The cough is typically dry and can persist for weeks after the initial infection has resolved.
• Other Likely Diagnoses
  • Asthma: Asthma can cause a chronic non-productive cough, especially at night or with exertion. The presence of wheezing, shortness of breath, or a history of allergies might support this diagnosis.
  • Gastroesophageal Reflux Disease (GERD): GERD can cause a non-productive cough due to the reflux of stomach contents into the esophagus, irritating the throat and triggering coughing. Symptoms of heartburn or regurgitation might accompany the cough.
  • Allergic Rhinitis: Postnasal drip from allergic rhinitis can cause a non-productive cough. Other symptoms might include sneezing, runny nose, and itchy eyes.
• Do Not Miss Diagnoses
  • Pneumonia: Although pneumonia typically presents with a productive cough, some cases (especially in the early stages or in certain types like pneumocystis pneumonia in immunocompromised patients) might have a non-productive cough. Fever, shortness of breath, and chest pain could be accompanying symptoms.
  • Pulmonary Embolism: A non-productive cough can be a symptom of a pulmonary embolism, especially if accompanied by sudden onset of shortness of breath, chest pain (worsening with deep breaths), or syncope.
  • Lung Cancer: A persistent non-productive cough in a smoker or someone with a history of smoking should raise concern for lung cancer. Other symptoms might include weight loss, hemoptysis, or recurrent pneumonia.
• Rare Diagnoses
  • Sarcoidosis: This is a systemic disease that can cause a non-productive cough among other symptoms like shortness of breath, chest pain, and skin or eye lesions.
  • Interstitial Lung Disease: A group of diseases that cause scarring or inflammation of the lung tissue, leading to a non-productive cough and shortness of breath.
  • Tuberculosis: Although more commonly associated with a productive cough, tuberculosis can present with a non-productive cough, especially in its early stages. Systemic symptoms like fever, night sweats, and weight loss might be present.

Each of these diagnoses has a different set of accompanying symptoms and risk factors that can help guide the diagnosis. A thorough history, physical examination, and diagnostic tests (such as chest X-rays, pulmonary function tests, or blood work) are essential for determining the underlying cause of a non-productive cough.