Differential Diagnosis for Worsening SOB, Dry Cough, and Right Shoulder Pain on Exertion

• Single Most Likely Diagnosis
  • Pulmonary Embolism (PE): This condition is highly plausible given the combination of worsening shortness of breath (SOB), dry cough, and pain that worsens with exertion, which could be referred pain from a PE.
• Other Likely Diagnoses
  • Pneumonia: Could explain the SOB and dry cough, and if the pneumonia is large or located near the diaphragm, it could refer pain to the shoulder.
  • Chronic Obstructive Pulmonary Disease (COPD) Exacerbation: Patients with COPD can experience worsening SOB and cough, and the shoulder pain could be related to increased work of breathing.
  • Pleurisy: Inflammation of the pleura can cause sharp chest pain that worsens with deep breathing or coughing, potentially radiating to the shoulder.
• Do Not Miss Diagnoses
  • Myocardial Infarction (MI): Although less likely given the dry cough and shoulder pain, an MI can present atypically, especially in women or diabetic patients, and is a potentially fatal condition if missed.
  • Pneumothorax: A collapsed lung can cause sudden onset of SOB and chest pain that could radiate to the shoulder, and is a medical emergency.
  • Lung Cancer: While less common, lung cancer can cause persistent cough, SOB, and chest or shoulder pain, especially if the tumor is located near the pleura or has metastasized.
• Rare Diagnoses
  • Pulmonary Vasculitis (e.g., Wegener's Granulomatosis): These conditions can cause a variety of respiratory and systemic symptoms, including cough, SOB, and chest pain.
  • Diaphragmatic Hernia: Although rare, a hernia through the diaphragm can cause respiratory symptoms and referred shoulder pain, especially if the hernia is large or becomes incarcerated.