Wolf's isotopic response: a case of zosteriform lichen planus

Lichen planus is a lichenoid disorder characterized by shiny, flat papules. In addition to the classical appearance, there are several variants. Zonal or zosteriform lesions have been described. A 25-year-old male with a complaint of increasing numbers of erythematous swellings on his left groin for twenty days was admitted to our out-patient clinic. He had a history of herpes zoster in the same localization which had been treated with topical acyclovir two weeks prior to his admission. Dermatological examination revealed multiple, shiny, erythematous, umblicated papules localized to the left inguinal region in a linear pattern. A biopsy was taken from the lesions. According to the clinical and pathological findings the diagnosis was zosteriform lichen planus. Zosteriform lichen planus is a rare variant of lichen planus; its differentiation from zona zoster and other linear dermatoses is difficult. We presented our case because of its rarity as a variant of lichen planus and its appearance in the area of healed herpes zoster as an isotopic response.