Differential Diagnosis

• Single most likely diagnosis
  • A. Emphysema: The patient's symptoms of a productive cough, increased AP chest diameter, and low FEV1/FVC ratio are consistent with emphysema, a type of chronic obstructive pulmonary disease (COPD). The patient's history of smoking also supports this diagnosis, as smoking is a major risk factor for emphysema.
• Other Likely diagnoses
  • B. Chronic bronchitis: Chronic bronchitis is another type of COPD that can present with a productive cough and low FEV1/FVC ratio. While the increased AP chest diameter is more characteristic of emphysema, chronic bronchitis can also cause hyperinflation of the lungs.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • D. TB (Tuberculosis): Although less likely, TB can present with a productive cough and low FEV1/FVC ratio. It is essential to consider TB in the differential diagnosis, especially in patients with risk factors such as smoking, as untreated TB can be fatal.
  • C. Pulmonary fibrosis: While pulmonary fibrosis typically presents with a dry cough and crackles on examination, it can occasionally cause a productive cough. It is essential to consider pulmonary fibrosis in the differential diagnosis, as it can be a progressive and fatal disease if left untreated.
• Rare diagnoses
  • Other rare diagnoses, such as cystic fibrosis or bronchiectasis, can also present with a productive cough and low FEV1/FVC ratio. However, these conditions are less likely in a 55-year-old patient with a history of smoking and are not as strongly supported by the patient's symptoms and examination findings.