Allergy 4 : Abnormal reaction to environmental substances such as pollens, dust, food, or microorganisms, in amounts that do not affect most people. (Webster)
Arizona Department of Health Services, Emergency Preparedness Glossary, Phoenix, Arizona, USA 2011. http://www.azdhs.gov/als/childcare/documents/prepa redness/emergency-preparedness-glossary.pdf, (Emr Prep - Amer) {846}