Primary cutaneous nocardiosis associated with intra-articular corticosteroid injection

A 65-year-old woman presented to our clinic with a 2-month history of papul opustular lesions on her right hand that had progressively increased in siz e and number. She had a 15-year history of psoriasis vulgaris and had devel oped digital arthralgias within the preceding few months. A diagnosis of ps oriatic 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, superfic ial. scaling nodules, measuring 0.5-1.5 cm, on the second and fourth metaca rpal bones and on the proximal phalanx of the fourth finger. Many scattered papulopustular lesions were also present on the back of the right hand (Fi g. 1). Routine laboratory investigations, including urine analysis, complete blood count, sedimentation rate, glucose, liver function tests, renal function t ests, total protein, and albumin were within normal limits. Chest X-ray and right hand roentgenogram were normal. Microbiological examination of the a spiration fluid obtained from the nodules revealed Grampositive, acid-resis tant, filamentous bacteria with fine branching. The isolates were grown wit hin 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 dail y for 6 weeks. It later became evident that the patient had stopped the tre atment within 3 weeks, when a dramatic improvement was observed (Fig. 2). N o recurrences were noted at 15 months.