erythema multiforme

[mŭl′tə-fôrmē]
n.
  1. A skin disease associated with allergies, seasonal changes, or drug sensitivities, and characterized by the acute eruption of red macules, papules, or subdermal vesicles on the skin and mucous membranes; the characteristic lesion consists of a papule surrounded by a concentric ring.herpes iris
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.