Causes of Allergic Reaction

Causes of Allergic Reaction

Almost anything can trigger an allergic reaction.

    * The body’s immune system involves the white blood cells, which produce antibodies.
          o When the body is exposed to an antigen, a complex set of reactions begins.
          o The white blood cells produce an antibody specific to that antigen. This is called “sensitization.”
          o The job of the antibodies is to detect and help destroy substances that cause disease and sickness. In allergic reactions, the antibody is called immunoglobulin E or IgE.
    * This antibody promotes production and release of chemicals and hormones called “mediators.
          o Mediators have effects on local tissue and organs in addition to activating more white blood cell defenders. It is these effects that cause the symptoms of the reaction.
          o Histamine is one of the better-known mediators produced by the body.
          o If the release of the mediators is sudden or extensive, the allergic reaction may also be sudden and severe, and anaphylaxis may occur.
    * Your allergic reactions are unique to you. For example, your body may have learned to be allergic to shellfish or other foods from repeated exposure.

    * Most people are aware of their particular allergy triggers and reactions.
          o Certain foods, vaccines and medications, latex rubber, aspirin, shellfish, dust, pollen, mold, animal dander, and poison ivy are well-known allergens.
          o Bee stings, fire ant stings, penicillin, and peanuts are known for causing dramatic reactions that can be serious and involve the whole body.
          o Minor injuries, hot or cold temperatures, exercise, or even emotions may be triggers of allergic reactions.
          o Often, the specific allergen cannot be identified unless you have had a similar reaction in the past.
    * Allergies and the tendency to have allergic reactions run in some families. You may have allergies even if they do not run in your family.

    * Many people who have one trigger tend to have other triggers as well.

    * People with certain medical conditions are more likely to have allergic reactions:
          o severe allergic reaction in the past
          o asthma
          o lung conditions that affect breathing, such as chronic obstructive pulmonary disease (COPD)
          o nasal polyps
          o frequent infections of the nasal sinuses, ears, or respiratory tract
          o sensitive skin