Morphea developing at the site of healed herpes zoster.

Wolf's isotopic response describes the occurrence of a new, unrelated disease that appears at the same location as a previously healed skin disease, and the most common primary skin disease of this phenomenon is herpes zoster. Several cutaneous lesions have been described to occur at the site of healed herpes zoster, and granulomatous dermatitis and granuloma annulare have been reported to be the most common second diseases. The pathogenesis of the isotopic response is still unclear. Morphea can develop at the site of regressed herpes zoster and a few such cases have been reported. We present here an additional case of morphea that developed at the site of previously healed herpes zoster, and we review the relevant literature.