What causes allergies?
An allergy is a reaction in the body to a normally harmless substance. Usually the immune system functions as the body’s defense against invading bacteria and viruses. In most allergic reactions, the immune system is responding to a false alarm. When kids inhale an allergen (a substance that causes allergies), their immune systems release chemical substances that inflame the linings of their noses, sinuses, eyelids, lungs and eyes. This causes itching, sneezing, runny nose, watery eyes, couching and wheezing.
Researchers think kids may inherit the tendency to be allergic. Children are more likely to develop allergies if a parent has allergies, though they may not be allergic to the same substance. Substances that cause the most allergic reactions include pollen, mold, dust, mites, and pets.
