Track

Case Reports

Abstract

A 59-year-old woman with multiple sclerosis and scleroderma (on methotrexate) presented with a painful rash involving the right lower extremity for 2 months, which started as a vesiculopustular eruption that was ulcerated at the time of presentation. Physical exam was notable for violaceous indurated papules, some which were ulcerated on the right buttock, knee, shin, and dorsal foot. The clinical differential diagnosis included infection, neutrophilic dermatosis, and vasculitis. Punch biopsy with tissue cultures was performed for further evaluation. Histopathology showed dermal necrosis and hemorrhage with a surrounding infiltrate composed of lymphocytes and mononuclear and multinucleated histiocytes. Within the necrotic regions of the dermis, there were cells that exhibited molding, multinucleation, and margination of peripheral chromatin. The herpes virus antigen I/II immunohistochemical stain was negative. Overall, the findings were consistent with a herpes zoster (HZ) infection. HZ is typically diagnosed clinically or with DNA PCR of vesicular fluid. Diagnosis, however, may be difficult in the absence of vesicles. Classic histopathology findings of herpes virus infections include steel grey nuclei, ballooning, acantholysis, multinucleated epithelial cells, and necrotic keratinocytes. HZ commonly affects hair follicle epithelium and can cause a vasculitis, which explains the necrosis and viral cytopathologic changes seen deeper in the dermis in our patient’s case. HZ can have a less acute presentation in immunosuppressed patients and thus be easily overlooked. It is important for dermatologists for to have a high index of suspicion for HZ to avoid long-term sequelae including postherpetic neuralgia.