LAUSR

Wolf's isotopic non response (WINR) denotes absence of an eruption at the site of another unrelated and already healed skin disease .1 Sunburn erythema primarily mediated by prostaglandin E2 is usually apparent a few hours after sun exposure, peaks at about 24 hours and gradually resolves over few days. Woronoff ring (WR) is a non erythematous or pale area of approximately same width around subsiding psoriatic plaques that fails to show erythema with ultraviolet (UV) light .2 We report an interesting and hitherto under reported case of acute sunburn which spared healed lesions of psoriasis along with a peripheral halo of apparently normal looking skin which possibly explains the underlying pathophysiology.