Cutaneous reactions following herpes zoster infections: report of three cases and a review of the literature.

Three patients, one healthy and two immunocompromised, developed cutaneous reactions that histologically mimicked granuloma annulare at sites of resolved varicella-zoster virus (VZV) reactivation infections. Variable latency periods between the infection and the granulomatous reaction were noted. As in other case reports, the presence of VZV DNA in these lesions was inconsistently demonstrated by the polymerase chain reaction (PCR) and appears more common in early, as opposed to late, post-zoster granulomas. In addition to various granulomatous reactions, vasculitic and neoplastic eruptions following resolved VZV infections have been described and are reviewed here. Therapeutically, topical, intralesional and systemic corticosteroids, as well as acyclovir, have been tried with inconsistent results. Although the pathogenesis remains unclear, the presence of VZV DNA in early lesions that histologically do not display viral cytopathic changes, suggests the virus induces an atypical delayed hypersensitivity reaction not affected by antiviral therapy.