Allergy is the term for a mistaken reaction to foreign substances by the immune system. “Mistaken” in that these foreign substances are usually harmless. The substances that trigger allergy are called allergens. Examples include pollens, dust mite, molds, danders, and certain foods. People with allergies are said to be allergic or atopic. Allergens cause the over-production of immunoglobulin E (IgE), an antibody we all have in small amounts which is designed to protect us from parasites. During the sensitization period in allergy, IgE is overproduced. It coats mast cells which contain histamine. Histamine causes inflammation and the typical allergic symptoms when released in the presence of allergens.