Nasal Septum Abscess Caused by Corynebacterium Amycolatum in a Young Immunocompetent Patient: Case Report

Corynebacterium species are part of the normal cutaneous and mucosal microbiota and may be classified as diphtheria-producing or nondiphtherial. Nondiphtherial species have gained prominence due to reports of respiratory, urinary, and occasional device-associated infections. Data on this species in Brazil remain scarce but are increasing. A previously healthy 17-year-old male was hospitalized with a 15-day history of nasal obstruction, high fever (39–40°C), thick mucous nasal secretions, and pulsatile frontal headache. Physical examination showed nasal pyramid bulging and a fleshy mass completely obstructing both nasal fossae. CT revealed a hypodense formation in both vestibules and nasal cavities with peripheral enhancement and mild palatal defect. Ceftriaxone plus clindamycin was initiated. Cranial CT showed frontal epidural empyema and anterior superior sagittal sinus thrombosis; anticoagulation was started. Endoscopic nasal drainage of a septal abscess was performed. Culture revealed Corynebacterium amycolatum , a result confirmed at the regional Central Laboratory by mass spectrometry. Susceptibility testing was not feasible. Vancomycin was initiated. After 9 days without radiologic improvement and development of marked eosinophilia attributed to drug reaction, therapy was switched to linezolid for 21 days. Neurosurgery drained the epidural empyema. After treatment modification and drainage, the patient improved and was cured. C. amycolatum infections have been increasingly reported, typically in immunocompromised individuals, premature neonates, and nosocomial settings. This case demonstrates invasive disease in a previously healthy young patient. It reinforces the importance of pursuing microbiological diagnosis even in healthy individuals, as unexpected pathogens may occur and show poor response to standard empiric therapy.