Differential Diagnosis for the Patient's Condition
The patient's pulmonary function test (PFT) results indicate a significant improvement in FEV1 after bronchodilator administration, suggesting a reversible airway obstruction. Based on the provided information, the differential diagnosis can be categorized as follows:
- Single Most Likely Diagnosis
- Moderate Persistent Asthma: The significant improvement in FEV1 (from 55% to 72% predicted) after bronchodilator administration strongly suggests asthma. The FEV1/FVC ratio also improves, although it remains below normal, indicating persistent airway obstruction. The patient's symptoms of worsening breathlessness and the PFT results align with moderate persistent asthma.
- Other Likely Diagnoses
- Mild COPD: Although the FEV1/FVC ratio is below 70%, indicating an obstructive pattern, the significant reversibility with bronchodilator (more than 15% increase in FEV1) is less typical for COPD. However, some patients with mild COPD may exhibit reversibility, making it a consideration.
- Moderate COPD: This is less likely due to the significant reversibility seen with bronchodilator administration, which is not characteristic of moderate COPD.
- Do Not Miss Diagnoses
- Alpha-1 Antitrypsin Deficiency: This genetic disorder can cause COPD-like symptoms in non-smokers or those with minimal smoking history. Although less likely, it's crucial to consider due to its significant implications for management and family screening.
- Cystic Fibrosis: Although rare in adults, cystic fibrosis can present with obstructive lung disease and should be considered, especially if other symptoms like recurrent infections or malabsorption are present.
- Rare Diagnoses
- Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): A rare autoimmune condition that can cause asthma-like symptoms along with eosinophilia and vasculitis.
- Allergic Bronchopulmonary Aspergillosis (ABPA): A condition that occurs in people with asthma or cystic fibrosis, characterized by an allergic reaction to Aspergillus fungi, leading to worsening respiratory symptoms.
Each of these diagnoses should be considered in the context of the patient's full clinical picture, including history, physical examination, and additional diagnostic tests as necessary.