What Is an Allergy?

 

An allergy is a physiological reaction caused when the immune system mistakenly identifies a normally harmless substance as damaging to the body.

Normally, the human body defends itself against harmful substances such as viruses or bacteria, but sometimes the defenses aggressively attack usually innocuous substances such as dust, mold, or pollen.

The immune system generates large amounts of the antibodies called immunoglobin E (IgE), a complex chemical weapon, to attack and destroy the supposed enemy. Each IgE antibody specifically targets a particular allergen—the substance that causes the allergy. In this disease-fighting process, inflammatory chemicals such as histamines, cytokines, and leukotrienes are released or produced, and some unpleasant (and, in extreme cases, life-threatening) symptoms may be experienced by an allergy-prone person.

Latest Allergy News
Many kids still exposed to secondhand smoke in cars

February 5, 2012 — NEW YORK (Reuters Health) - A new government study reports that while fewer kids and teens are getting exposed to secondhand smoke while riding in the car, rates of exposure are still high enough to warrant concern.

Traffic-related asthma costs two cities big money

February 3, 2012 — NEW YORK (Reuters Health) - Traffic pollution may cost two California cities millions each year in managing children's asthma, a new study suggests.

Breastfeeding tied to stronger lungs, less asthma

February 2, 2012 — NEW YORK (Reuters Health) - Kids who were breastfed as babies may have better lung function, and a lower risk of asthma, than those who were formula-fed, two new reports suggest.

Select news items provided by Reuters Health