Primary cutaneous nocardiosis associated with intra-articular corticosteroid injection

A 65-year-old woman presented to our clinic with a 2-month history of papulopustular lesions on her right hand that had progressively increased in size and number. She had a 15-year history of psoriasis vulgaris and had developed digital arthralgias within the preceding few months. A diagnosis of psoriatic arthropathy was made and she was treated by multiple intraarticular steroid injections on the back of the right hand. One month after the last injection, the lesions had developed over the treatment area. The patient had no apparent history of trauma, but had grown flowers for years. Dermatologic examination revealed three fluctuating, erythematous, superficial. scaling nodules, measuring 0.5-1.5 cm, on the second and fourth metacarpal bones and on the proximal phalanx of the fourth finger. Many scattered papulopustular lesions were also present on the back of the right hand (Fig. 1). Routine laboratory investigations, including urine analysis, complete blood count, sedimentation rate, glucose, liver function tests, renal function tests, total protein, and albumin were within normal limits. Chest X-ray and right hand roentgenogram were normal. Microbiological examination of the aspiration fluid obtained from the nodules revealed Grampositive, acid-resistant, filamentous bacteria with fine branching. The isolates were grown within a few days in blood agar and within a week in Lowenstein-Jensen medium. The microorganism was identified as Nocardia brasiliensis. The patient was given trimethoprim/sulfamethoxazole (160/800 mg) twice daily for 6 weeks. It later became evident that the patient had stopped the treatment within 3 weeks, when a dramatic improvement was observed (Fig. 2). No recurrences were noted at 15 months.