Abstract: A 76-year-old male patient who presented with localized erythema, swelling, and pain in the right upper limb for one week. Dermatological examination revealed an approximately 8 cm×3 cm erythematous ulcer with purulent discharge near the right elbow joint, and beaded red nodules of varying sizes on the right upper arm. Laboratory tests showed elevated white blood cell count and hypersensitivity C-reactive protein. Bacterial culture yielcled positive for Nocardia brasiliensis. Diagnosis of primary cutaneous nocardiosis was made. The patient was administered oral trimethoprim sulfamethoxazole together with local symptomatic treatment. Complete recovery was achieved after 50 days of therapy, and no recurrence occurred during the six-month follow-up.

Key words: primary cutaneous nocardiosis, Nocardia brasiliensis, trimethoprim sulfamethoxazole