Differential Diagnosis for Dry Cough

• Single most likely diagnosis
  • Postnasal drip (upper airway secretion syndrome): This is a common cause of dry cough, especially when associated with rhinorrhea or sneezing, as it suggests an allergic or infectious process affecting the upper respiratory tract.
• Other Likely diagnoses
  • Allergic rhinitis: Symptoms such as sneezing and rhinorrhea in the context of a dry cough suggest an allergic component, making allergic rhinitis a plausible diagnosis.
  • Viral upper respiratory infection: Many viral infections can cause a dry cough along with rhinorrhea and sneezing, making this a common and likely diagnosis.
  • Asthma: Cough can be a predominant symptom of asthma, especially if it's exercise-induced or related to allergens, and may be accompanied by other symptoms like wheezing or shortness of breath, though these might not always be present.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Pneumonia: Although pneumonia typically presents with more severe symptoms like fever, chills, and productive cough, atypical presentations, especially in the elderly or immunocompromised, can be subtle, including a dry cough.
  • Pulmonary embolism: A sudden onset of dry cough, especially if accompanied by other symptoms like chest pain or shortness of breath, could indicate a pulmonary embolism, which is a medical emergency.
  • Tuberculosis: A chronic dry cough can be a symptom of tuberculosis, especially in high-risk populations or those with exposure history.
• Rare diagnoses
  • Sarcoidosis: This autoimmune disease can cause a dry cough among other symptoms like shortness of breath and chest discomfort, due to granulomatous inflammation in the lungs.
  • Eosinophilic pneumonia: A rare condition characterized by an accumulation of eosinophils in the lungs, which can cause a dry cough along with other respiratory symptoms.
  • Interstitial lung disease: A broad category of diseases affecting the lung interstitium, which can cause a dry cough, often accompanied by progressive shortness of breath.