Successful management of Nocardia farcinica brain abscess in an immunocompetent adult with trimethoprim/sulfamethoxazole hypersensitivity: A case report and review

Abstract

Background: Nocardia farcinica brain abscesses are rare in immunocompetent individuals. Trimethoprim/sulfamethoxazole (TMP/SMX) is first-line therapy, but hypersensitivity reactions necessitate alternative regimens. This report details successful management in a TMP/SMX-allergic patient.

Case report: A 38-year-old immunocompetent male presented with recurrent seizures. MRI revealed expanding left frontal lobe lesions. Surgical excision and metagenomic next-generation sequencing (mNGS) confirmed N. farcinica. Due to hypersensitivity to TMP/SMX, an alternative antibiotic regimen consisting of intravenous imipenem/cilastatin for 18 days and amikacin for 7 days was administered, followed by oral amoxicillin for 435 days and minocycline for 252 days. This therapeutic approach resulted in effective infection control, as evidenced by sustained clinical improvement over a 28-month follow-up period.

Conclusion: N. farcinica brain abscess can occur in immunocompetent adults, posing therapeutic challenges with TMP/SMX intolerance. This case demonstrates that alternative regimens-imipenem/cilastatin, amikacin, amoxicillin, and minocycline-can achieve sustained remission. Individualized therapy based on drug susceptibility and patient factors is critical.

Keywords: Brain abscess; Immunocompetent; Intolerance; Nocardia farcinica; Successful management; Trimethoprim/sulfamethoxazole.