Wolf Isotopic Response Manifesting as Postherpetic Granuloma Annulare A Case Series

Context.-Wolf isotopic response has infrequently been reported in the literature, mainly as isolated case reports. Objective.-To aid in recognition of the occurrence of postherpetic granuloma annulare for accurate histologic interpretation of granulomatous dermatitides. Design.-We report 5 cases of patients with Wolf isotopic response manifesting as granuloma annulare, developing in a site of previous herpes zoster, and discuss the clinicopathologic findings. Results.-Previous infection with herpes zoster or herpes simplex virus was found in 5 of 5 cases reported. The differential diagnosis of a dermal lymphohistiocytic infiltrate with multinucleated giant cells includes postherpetic granuloma annulare. Conclusions.-All cases of postherpetic Wolf isotopic response reported in this series revealed granuloma annulare, with a perineurovascular or perifollicular pattern of lymphohistiocytic infiltration including multinucleated giant cells, and occurred following herpes zoster or herpes simplex infection, although herpes viral infection was not always associated with a subsequent isotopic eruption. Awareness of this entity can aid in the clinicopathologic diagnosis of granuloma annulare occurring at the site of prior herpes viral infection.