Severe gangrene accompanied by varicella zoster virus-related vasculitis mimicking rheumatoid vasculitis

Herpes zoster infection occurs more frequently and severely in immunosuppressed populations. However, the condition sometimes presents with atypical clinical manifestations of the skin, which makes it difficult to reach a correct diagnosis. We experienced a case of acral gangrene caused by varicella zoster virus (VZV)-related vasculitis in a rheumatoid arthritis (RA) patient. Histologically, necrotic vasculitis was observed; however, there were initially no findings in the epidermis suggestive of a viral infection. We thought that the skin ulcer was related to rheumatoid vasculitis. However, an immunohistochemical analysis for VZV confirmed VZV infection in the vascular endothelium of the dermis, leading to effective treatment with intravenous acyclovir. Since various pathogenic skin phenotypes are observed in RA patients, modified according to the status of immunosuppression, clinicians must recognize the variation in typical and atypical manifestations in order to manage these patients.