A 47-year-old woman who keeps pigeons presents with four months of progressive exertional dyspnea and malaise. HRCT shows diffuse centrilobular ground-glass nodules with mosaic attenuation, and expiratory images demonstrate lobular air trapping. Pulmonary function tests show a restrictive pattern with reduced DLCO. Transbronchial biopsy shows poorly formed non-caseating granulomas near small airways. What is the single most important step in her management?

• A Complete avoidance of further antigen exposure ✓
• B Lifelong low-dose corticosteroids
• C Antifungal therapy with itraconazole
• D Lung transplantation assessment

Explanation

Subacute hypersensitivity pneumonitis from avian antigens is confirmed by centrilobular nodules, mosaic perfusion, air trapping on expiratory CT, and poorly formed granulomas. Removal from antigen exposure is the cornerstone of management and may alone reverse disease; corticosteroids are added for significant inflammation but are secondary. Antifungals have no role because the disorder is an immune reaction to inhaled organic antigen, not infection. Transplantation applies only to end-stage fibrotic disease.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.