1. Health

Allergy

From , former About.com Guide

Updated May 05, 2008

About.com Health's Disease and Condition content is reviewed by our Medical Review Board

Definition: An allergy is any immune system reaction involving Immunoglobulin E to a substance usually thought of as benign, such as food or pollen.
Also Known As: allergic reaction

©2012 About.com. All rights reserved.

A part of The New York Times Company.

We comply with the HONcode standard
for trustworthy health
information: verify here.