Secondary Syphilid Developing Over Healed Lesions of Varicella: Wolf's Isotopic Response?

Isotopic response is a distinctive phenomenon in which a new skin disorder occurs at the site of another, unrelated, and already healed skin disease. Most of the cases documented in the literature were associated with herpes zoster as primary disease while the list of "second" diseases is quite long. We report here a hitherto unreported occurrence of isotopic response in which secondary syphilis occurred on the healed lesions of varicella.