Differential Diagnosis for Patient with Dry Cough for 3 Weeks
- Single Most Likely Diagnosis
- Postnasal drip (upper airway secretion syndrome): This is a common cause of dry cough, especially if the patient has a history of allergies, sinusitis, or a recent upper respiratory infection. The cough is often worse at night and can be accompanied by a sensation of mucus running down the back of the throat.
- Other Likely Diagnoses
- Asthma: Cough can be a sole presenting symptom of asthma, especially in non-allergic individuals. The cough may be worse at night or with exertion.
- Gastroesophageal reflux disease (GERD): Stomach acid can reflux into the esophagus and trigger a cough. This cough is often worse at night or after eating.
- Influenza or other viral respiratory infections: Although the cough has been present for 3 weeks, some viral infections can cause a prolonged cough.
- Allergic rhinitis: Similar to postnasal drip, allergic rhinitis can cause a dry cough due to the release of histamine and other mediators.
- Do Not Miss Diagnoses
- Pulmonary embolism: Although less common, a dry cough can be a presenting symptom of a pulmonary embolism, especially if accompanied by chest pain, shortness of breath, or hemoptysis.
- Lung cancer: A persistent dry cough can be a symptom of lung cancer, especially in smokers or those with a history of smoking.
- Tuberculosis: A chronic dry cough can be a symptom of tuberculosis, especially in immunocompromised individuals or those from endemic areas.
- Pneumonia: Bacterial or viral pneumonia can cause a dry cough, especially if the infection is localized to the upper lobes.
- Rare Diagnoses
- Sarcoidosis: A systemic disease that can cause granulomatous inflammation in the lungs, leading to a dry cough.
- Eosinophilic pneumonia: A rare condition characterized by an accumulation of eosinophils in the lungs, which can cause a dry cough.
- Bronchiectasis: A condition characterized by permanent dilation of the bronchi, which can cause a chronic dry cough.
- Interstitial lung disease: A group of diseases that cause inflammation and scarring in the lungs, which can lead to a dry cough.