Differential Diagnosis for 66-year-old Female with Fatigue, Joint Pain, and Chronic Cough
Single Most Likely Diagnosis
- Gastroesophageal Reflux Disease (GERD): The chronic cough, worse at night, and postnasal drip, along with normal chest X-ray and spirometry, suggest GERD as a possible cause. The small response to bronchodilator may indicate some airway reactivity, but the primary issue seems to be non-pulmonary.
Other Likely Diagnoses
- Rheumatoid Arthritis (RA): Given the joint pain affecting multiple joints and muscle aches, RA is a consideration, especially in the context of fatigue. However, the absence of specific markers (e.g., rheumatoid factor, anti-CCP) and the normal CBC make this less clear.
- Chronic Sinusitis: The postnasal drip and chronic cough could be indicative of chronic sinusitis, which can also contribute to fatigue and muscle aches due to the chronic nature of the condition.
- Asthma: Although spirometry was normal with only a small response to bronchodilator, asthma should be considered, especially if symptoms are intermittent and variable. The cough worse at night is consistent with asthma.
Do Not Miss Diagnoses
- Lung Cancer: Despite a normal chest X-ray, lung cancer can present with chronic cough and should not be missed, especially in a patient of this age group. Further imaging (e.g., CT scan) might be warranted.
- Sarcoidosis: This condition can cause cough, joint pain, and fatigue, and while less common, it's critical not to miss due to its potential for serious complications.
- Interstitial Lung Disease (ILD): ILD can present with chronic cough and fatigue, and a high-resolution CT scan might be necessary to evaluate for this condition, especially if other symptoms or findings suggestive of ILD are present.
Rare Diagnoses
- Relapsing Polychondritis: A rare autoimmune disorder that can cause joint pain, fatigue, and respiratory symptoms, including chronic cough.
- Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): A rare condition characterized by asthma, eosinophilia, and vasculitis, which could explain some of the patient's symptoms, although it would be unusual without eosinophilia noted on the CBC.