erythema chronicum migrans

[krŏnĭ-kəm mīgrănz′]
n.
  1. A raised erythematous ring on the skin having hard borders and a central clearing, and radiating from the site of an insect bite; it is the characteristic lesion of Lyme disease.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.