Abstract
RATIONALE: Bronchoscopy with bronchoalveolar lavage (BAL) is essential for diagnosing pulmonary infections; however, its potential to iatrogenically disseminate a localized Nocardia infection represents a severe and unreported risk. This case aims to alert clinicians to this danger and underscore essential therapeutic lessons for disseminated disease. PATIENT CONCERNS: A 51-year-old immunocompetent woman with longstanding bronchiectasis presented with 1-day of hemoptysis and a 40-year history of chronic cough and sputum production. These symptoms had worsened over the preceding 2 months despite broad-spectrum antibiotic therapy. DIAGNOSES: Bronchiectasis was diagnosed based on chronic respiratory symptoms and characteristic computed tomography findings. Nocardia terpenica infection was confirmed by BAL fluid culture and metagenomic next-generation sequencing. Within 24 hours post-BAL, the patient developed fever, respiratory failure, and new bilateral consolidations on computed tomography, indicating procedure-related disseminated nocardiosis. INTERVENTIONS: Diagnostic bronchoscopy with BAL was performed. Therapeutically, the patient received a total of 24 days of intensive combination therapy with intravenous imipenem/cilastatin and oral trimethoprim-sulfamethoxazole (TMP-SMX), followed by sequential long-term oral TMP-SMX monotherapy. OUTCOMES: The initial 10-day course of combination therapy led to rapid clinical improvement, with resolution of fever and respiratory failure within 3 days, and normalization of C-reactive protein levels by day 10. Radiographic improvement was also evident. However, relapse (recurrent fever and malaise) occurred promptly within 3 days after de-escalation to TMP-SMX monotherapy. After reinstitution of imipenem/cilastatin plus TMP-SMX for an additional 14 days (totaling 24 days of intensive therapy), the patient achieved sustained clinical and radiographic remission. She was successfully discharged on long-term TMP-SMX monotherapy and remained well at the 2-month follow-up. LESSONS: This is the first report suggesting that bronchoscopy, particularly BAL, can disseminate a localized airway Nocardia infection, causing acute disseminated pulmonary nocardiosis. Extreme caution is warranted when performing bronchoscopy in bronchiectasis patients with suspected or confirmed nocardiosis. For disseminated pulmonary nocardiosis, intensive combination therapy for at least 3 weeks is mandatory to prevent relapse, regardless of a rapid initial response.