Allergies are a physiological error. The body reacts negatively to harmless substances, foods or stimuli. The word “allergy” comes from the Greek allos, meaning “other”. It was first used in 1906 to refer to an "altered reaction" in the body's immune system.
An allergic reaction occurs when the body comes in contact with the allergen. This can occur through contact with the skin, inhalation, injection or ingestion of the substance.
more ...