Nocardia yamanashiensis in an immunocompromised patient presenting as an indurated nodule on the dorsal hand

Background. Nocardia are ubiquitous, aerobic, gram-positive actinomycetes. Nocardiosis typically occurs in immunocompromised patients, although immunocompetent individuals can also be affected. Purpose. The purpose of this case study is to review the clinical characteristics and treatments of a unique form of cutaneous nocardiosis. Materials and methods. We retrospectively reviewed the medical literature using PubMed, searching the terms cutaneous, host, immunocompromised, Nocardia, primary, yamanashiensis. Patient reports and previous reviews of the subject were critically assessed and the salient features are presented. Results. Cutaneous nocardiosis typically presents as pustular nodules and the lesions may progress to become abscesses, cellulitis, granulomas or keloid-like tumors. N. brasiliensis is the predominant species involved in primary cutaneous nocardiosis; other common Nocardia species involved in human disease are N. farcinica, N. abscessus, N. cyriacigeorgica, and N. nova. Only two individuals (including the patient presented here) with primary cutaneous infection by N. yamanashiensis have been described in the literature; a third clinical isolate was recovered from a lung biopsy. Conclusion. Nocardia yamanashiensis is a rare clinical form of primary cutaneous nocardiosis. 16S ribosomal gene sequencing, as well as Gram stain and modified Fite acid-fast stain, play a vital role in identifying this clinical variant.