Differential Diagnosis for a 76-year-old Male with Bronchiectasis and Cough

Single Most Likely Diagnosis

• Exacerbation of Bronchiectasis: Given the patient's history of bronchiectasis and presenting symptom of cough, an exacerbation of the underlying condition is the most likely diagnosis. Bronchiectasis is characterized by chronic inflammation and infection of the bronchi, leading to persistent cough and sputum production. An exacerbation could be triggered by a bacterial infection, viral respiratory infection, or environmental factors.

Other Likely Diagnoses

• Community-Acquired Pneumonia: Although the chest X-ray was normal 10 days ago, pneumonia can develop rapidly, especially in older adults or those with underlying lung disease. The patient's symptoms of cough could be indicative of a new infection.
• Chronic Obstructive Pulmonary Disease (COPD) Exacerbation: If the patient also has COPD, an exacerbation could present with increased cough, sputum production, and shortness of breath.
• Influenza or Other Viral Respiratory Infections: These can cause cough and may be more severe in individuals with underlying lung conditions like bronchiectasis.

Do Not Miss Diagnoses

• Lung Cancer: Although less likely, it is crucial not to miss lung cancer, especially in a patient with a history of lung disease and new or changing symptoms. Cough can be an early symptom of lung cancer.
• Pulmonary Embolism: This is a potentially life-threatening condition that can present with cough, among other symptoms like shortness of breath and chest pain. It's essential to consider, especially if there are risk factors or a sudden onset of symptoms.
• Tuberculosis (TB): Reactivation or new infection with TB can occur in individuals with chronic lung conditions and can present with cough, weight loss, and other systemic symptoms.

Rare Diagnoses

• Allergic Bronchopulmonary Aspergillosis (ABPA): This condition occurs in people with asthma or cystic fibrosis but can also be seen in those with bronchiectasis. It's characterized by an allergic reaction to Aspergillus fungi, leading to worsening respiratory symptoms.
• Bronchiolitis Obliterans: A rare condition that can follow a respiratory infection, leading to obstruction of the small airways. It's more common in lung transplant recipients but can occur in others with significant lung injury or disease.