Primary cutaneous nocardiosis: a pitfall in the diagnosis of skin infection

Excerpt

A 73-year-old male with no relevant past medical history presented with a painful lesion in left lower leg of 2 weeks’ duration (Fig. 1). The patient reported that the cutaneous lesions started as an erythema, which progressed in size and became tender. The patient denied contact with animals and travel history, but had been handling plants the previous weeks. He did not recall any trauma. A skin biopsy was performed. Following local antibiotic guidelines, empiric therapy for skin cellulitis with amoxicillin/clavulanate 875/125 mg q8h for 2 weeks was prescribed. The histological analysis revealed an abscessified dermo-hypodermic inflammation suggestive of an infectious process (Fig. 2). Three weeks later filamentous Gram-positive rods compatible with Nocardia sp. were isolated in the culture media from the biopsy sample (Fig. 3). Nocardia brasiliensis was finally identified by ribosomal sequencing. The patient was diagnosed with primary cutaneous nocardiosis. After 1 year of follow-up the patient remains asymptomatic (Fig. 4).

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