Sinobronchial Syndrome Patients with Suspected Non-Tuberculous Mycobacterium Infection Exacerbated by Exophiala dermatitidis Infection

BACKGROUND: Exophiala dermatitidis is an environmental black fungus that rarely causes respiratory infections, yet its pathophysiological features and treatment regimens have not been established. CASE SERIES: Two cases of exacerbations of chronic bronchitis and sinusitis due to E. dermatitidis infection in Japan are presented. Both patients were women, and non-tuberculous Mycobacterium (NTM) infection was suspected based on chest radiological findings, but E. dermatitidis was detected from bronchial lavage fluid and nasal mucus, respectively. Both cases were successfully treated by antifungal agents such as liposomal amphotericin B, voriconazole, and itraconazole, but clarithromycin, rifampicin, ethambutol, and sitafloxacin for NTM were not effective. CONCLUSION: E. dermatitidis can become a respiratory pathogen, especially in patients with chronic sinobronchial syndrome.