What is the diagnosis for a 31-year-old female smoker with a persistent productive cough, worsened by night and exertion, with associated wheezing and vomiting, despite treatment with doxycycline (Doxycycline), Robitussin (Guaifenesin), Mucinex (Guaifenesin), Flonase (Fluticasone), Singulair (Montelukast), and albuterol (Albuterol) inhaler, following exposure to human metapneumovirus 2.5 months prior?

Differential Diagnosis for a 31-year-old Female with Cough

Single Most Likely Diagnosis

• Chronic Bronchitis: This diagnosis is likely due to the patient's history of smoking and the presence of a productive cough that has persisted for over a month. The cough is worse at night and associated with wheezing, which are common symptoms of chronic bronchitis. The lack of response to antibiotics and the presence of shortness of breath with exertion also support this diagnosis.

Other Likely Diagnoses

• Postnasal Drip: Although the patient denies nasal congestion or rhinorrhea, her history of seasonal allergies and the recent restart of Flonase and Singulair suggest that postnasal drip could be contributing to her cough.
• COPD: Given the patient's smoking history, COPD is a possible diagnosis, especially with symptoms of shortness of breath with exertion and a productive cough.
• Acid Reflux: The patient's cough is worse at night and can be forceful enough to elicit vomiting, which could suggest acid reflux as a contributing factor.

Do Not Miss Diagnoses

• Pulmonary Embolism: Although the patient does not have typical symptoms such as chest pain or fever, a pulmonary embolism can present with cough and shortness of breath, making it a diagnosis that should not be missed.
• Lung Cancer: Given the patient's smoking history, lung cancer is a possibility, although it is less likely in a 31-year-old.
• Tuberculosis: The patient's exposure to a respiratory virus and lack of response to antibiotics make tuberculosis a diagnosis that should be considered, especially if she has been exposed to someone with TB.

Rare Diagnoses

• Cystic Fibrosis: Although the patient's age and lack of other symptoms make this diagnosis less likely, cystic fibrosis can present with a chronic cough and shortness of breath.
• Sarcoidosis: This diagnosis is possible, although less likely, given the patient's symptoms of cough and shortness of breath, and could be considered if other diagnoses are ruled out.
• Bronchiectasis: This diagnosis is also possible, given the patient's symptoms of a productive cough and shortness of breath, and could be considered if other diagnoses are ruled out.