A<unk>  is an allergy to a<unk> , most commonly a medication, and is a form of adverse<unk>  reaction. Medical attention should be sought immediately if an allergic reaction is suspected. An allergic reaction will not occur on the first exposure to a substance. The first exposure allows the body to create antibodies and memory lymphocyte cells for the antigen. However,<unk> s often contain many different substances, including dyes, which could cause allergic reactions. This can cause an allergic reaction on the first administration of a<unk> . For example, a person who developed an allergy to a red dye will be allergic to any new<unk>  which contains that red dye. A<unk>  is different from an intolerance. A<unk>  intolerance, which is often a milder, non-immune-mediated reaction, does not depend on prior exposure.
Drug allergy
Metal allergy
Food allergy
Nickel allergy
Wheat allergy
Animal allergy
Sesame allergy
Garlic allergy