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What causes allergy?
Certain substances,called allergens,trigger an allergic response in susceptible individuals.
They enter our bodies in a variety of ways:
- Inhaled into the nose and the lungs.
Examples are airborne pollens of certain trees, grasses and weeds; house dust that include dust mite particles, mold spores, and cat and dog dander.
- Ingested by mouth
.
Frequent culprits include shrimp, peanuts and other nuts.
- Injected
, such as reactions to penicillin,
several other injectable drugs, and stinging insect venom.
- Absorbed through the skin
:
poison ivy, sumac and oak.
These allergens react with antibodies(certain molecules in the immune system)in the allergic person,causing the production of histamine and
other chemical substances that cause various symptoms.Thus begins a chain reaction know as allergic response.For example,you may be allergic to pollen.During certain seasons,when the pollen count is high,exposure to
pollen(the allergen)sparks an allergic response in your body. This causes histamine release,which leads to sneezing,watery nasal drainage,tearing eyes,and other symptoms we know as allergy.The nasal symptoms of
allergy are termed allergic rhinitis. |
