allergic reaction

n.
  1. A local or generalized reaction of an organism to internal or external contact with a specific allergen to which the organism has been previously sensitized.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Related Words for allergic reaction

susceptibility, sensitivity, aversion, vulnerability, hypersensitivity