Cutibacterium acnes Pneumonia in an Immunocompromised Patient: A Case Report and Review of the Literature.

Cutibacterium acnes (C. acnes), known previously as Proprionebacterium acnes, is a common skin and mucous membrane colonizing bacteria. On rare occasions it has been associated with invasive infections in both immunocompetent and immunosuppressed patients. We describe the case of a 55-year-old female with a history of Sjogren's syndrome and psoriatic arthritis on TNF-alpha inhibitor therapy with etanercept. She presented with signs and symptoms of a thoracic infection with pulmonary nodules, hilar adenopathy, and bronchiectasis on thoracic computed tomography. She was diagnosed with C. acnes pneumonia based on culture growth from both endoscopic bronchial ultrasound transbronchial lymph node needle biopsy and navigational bronchoscopy transbronchial lung biopsy. Our patient noticed marked symptom relief and radiographic pulmonary parenchymal improvement with intravenous ceftriaxone provided for a six-week course. This case highlights the potential invasive disease caused by C. acnes, a common skin commensal.