Abstract
Wolf's post-zoster isotopic response refers to the occurrence of an unrelated new skin disorder at the same site of a healed skin lesion. Mechanism of this dermatological phenomena after herpes zoster infection remains unclear. In this study, we present three rare cases of eosinophilic dermatitis following herpes zoster infection. Erythematous infiltrative plaques or scattered red papules were found in all patients after remission of a previous herpetic infection. Skin biopsy revealed dermal perivascular eosinophilic infiltration, which was histologically confirmed as eosinophilic dermatitis. Based on the clinical timeline and histopathological characteristics, we supposed that the secondary lesion to be an isotopic response of Wolf. Skin lesion in one of the current patients overlapped with her tattoo, suggesting that tattoos might also predispose patients to post-zoster isotopic events. Topical corticosteroid was applied and all patients achieved remission. We also summarize the epidemiological, clinical and histopathological characteristics of the post-zoster eosinophilic dermatitis based on review of previous literature focusing on Wolf's isotopic response and secondary inflammatory dermatological disorders.