Login - or - Learn
Contact Us     Maps & Directions     About Us
Find a Provider
Your Medical Home
Find a Facility
Plan Your Visit
Find a Provider
Giving
Mother Frances Hospital
Heart Hospital
Neuroscience Institute
Orthopedics and Sports Medicine
Search Health Information    Allergic Reaction

Allergic Reaction

An allergic reaction is an overreaction of the immune system to a substance called an allergen. Allergens include chemicals, foods, medicines, mold, plants, and pollen.

Symptoms of an allergic reaction can range from mild and annoying to severe and life-threatening.

  • Allergens can affect different tissues in the body, such as the airways, eyes, gastrointestinal tract, nose, lungs, and skin.
  • Some allergic reactions, such as hives or itching around an insect bite or where a plant or chemical touched the skin, affect only one area of the body.
  • Other allergic reactions may affect the whole body, causing itching, swelling, or difficulty breathing.
  • A severe allergic reaction (called anaphylaxis) can lead to shock and even death.

Allergic reactions do not occur the first time a person is exposed to an allergen. A person may become more sensitive to the allergen with each exposure.

Last Revised: April 29, 2011

Author: Healthwise Staff

Medical Review: William H. Blahd, Jr., MD, FACEP - Emergency Medicine & H. Michael O'Connor, MD - Emergency Medicine

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

© 1995-2013 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

 
Trinity Clinic

Trinity Clinic is the area's preferred multispecialty medical group, with over 350 physicians and mid-level providers representing 40 specialties in 36 clinic locations serving East Texas.

Find a Trinity Clinic ProviderMedical Providers Directory  About Trinity Clinic MyChart

TMFHC app on iTunes

TMFHC app on Android Market