Wolf isotopic response has infrequently been reported in the literature, mainly as isolated case reports.
To aid in recognition of the occurrence of postherpetic granuloma annulare for accurate histologic interpretation of granulomatous dermatitides.
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.
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.
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.