Atypical Mycobacterial Infection of the Orbit

Purpose: To describe the clinical presentation and successful management of an orbital infection caused by Mycobacterium abscessus, a formerly unrecognized cause of orbital disease after penetrating trauma. Methods: An orbital infection due to M. abscessus is described, and previously reported ocular and extraophthalmic infections caused by M. abscessus are reviewed. Results: A 5-year-old boy had acute, painless visual loss shortly after being struck in his left lower eyelid with a fishing rod. Radiologic evaluation established a mass in the orbital apex. Initial biopsy and cultures of the apex mass were negative; however, additional orbital exploration and cultures demonstrated M. abscessus to be the causative organism. The orbital infection was treated successfully with long-term oral clarithromycin. Review of the literature on ocular/adnexal and soft tissue infections caused by atypical mycobacteria shows characteristic clinical and histopathologic features. Conclusions: To the authors' knowledge, only seven patients with atypical mycobacterial infections of the ocular adnexa have been reported. The patient reported in the current study illustrates the difficulty in establishing the preoperative diagnosis of atypical mycobacterial infections of the orbit. A chronic draining wound or a localized orbital abscess, after penetrating trauma, should alert the physician to the possibility of an M. abscessus infection. Clarithromycin, an oral macrolide antibiotic, appears to be the most effective medical therapy for these patients.