Detection of varicella-zoster virus in two dermatomes of herpes zoster duplex bilateralis in an immunocompetent host

An 85-year-old woman with no history of herpes zoster (HZ) presented with a primary lesion of erythema and blistering on her left thigh and a secondary similar lesion on her right chest which had appeared at 4 and 3 days before presentation, respectively. Tzanck smears for both lesions were positive, revealing multinucleated giant cells. Immunochromatography to detect varicella-zoster virus (VZV) antigen (DermaQuick & REG;VZV) showed positive on the left thigh at initial onset but negative on the right chest at subsequent onset. The latter repeatedly tested negative for VZV by DermaQuick & REG;VZV. A skin biopsy of the subsequent onset area revealed giant cells, and inclusion bodies were observed in the epidermis. Immunohistochemical staining with anti-VZV antibody and polymerase chain reaction to detect VZV DNA were positive. The patient was diagnosed with HZ duplex bilateralis and treated with acyclovir. The right thoracic region of the posterior part of the lesion became negative for DermaQuick & REG;VZV. It is thought that expression of viral antigens was suppressed in the right thoracic region, i.e., the late-onset area.