Severe Gangrene Accompanied by Varicella Zoster Virus-Related Vasculitis Mimicking Rheumatoid Vasculitis
A 72-year-old male who had been under treatment for RA with methotrexate (8 mg/week), prednisolone (5 mg/day) and bucillamine (200 mg/day) developed a skin ulcer on the left fifth toe and lymphadenitis on the left inguinal region. Although Streptococcus haemolyticus was detected in the skin ulcer and systemic antibiotics were administered, the skin ulcer expanded in size and depth, exposing the extensor tendon, and another ulcer consistent with scattered necrosis subsequently appeared on the dorsum of the left foot. A microscopic test for superficial mycoses, the Tzanck test and a cultivation test for mycobacterial infection were all negative. Furthermore, subcutaneous nodules also appeared on the left patella. A biopsy specimen obtained from the skin around the ulcer and subcutaneous nodule showed necrotic vasculitis although there were no remarkable changes in the epidermis, and we were concerned that the patient had progressed to rheumatoid vasculitis. Two months later, the ulcer on the fifth toe had further expanded with surrounding small erythematous, bullous lesions, while the other ulcer on the dorsal foot had become deeper, exposing the joint capsule (fig. ). A skin biopsy of the bullous lesion revealed acantholysis and ballooning degeneration of keratinocytes. Leukocytoclastic vasculitis with fibrinoid degeneration was also seen in the reticular dermis and subcutaneous tissue as it was in the findings from the first biopsy specimen (fig. ). Immunohistochemical staining using a monoclonal antibody recognizing VZV (Novocastra Laboratories, Newcastle, UK) was positive in keratinocytes inside the vesicles, fibroblasts, inflammatory cells and endothelial cells in the underlying dermis (fig. ). VZV was identified on a virological culture of a swab.\nWe also performed immunohistochemistry for VZV in the first biopsy specimen and confirmed positive staining in the cells in the dermis and subcutaneous tissue, including endothelial cells, with negative staining in keratinocytes (fig. ). These results indicated that our patient initially developed VZV vasculitis without the epidermal involvement typical of VZV infection. We considered the possibility of repeated VZV reactivation within several months due to immunosuppression. A decreased serum IgG level was also observed on a serological examination. We stopped the methotrexate therapy and started treatment with intravenous acyclovir. The expansion of the ulcer quickly stopped, and the lesion healed within 3 months without surgical treatment.