An Allergy is a hypersensitivity of the body to any substance. This substance can be any chemical ingredient, product, hair, dust, pollen or a germ.
Today it is well established that allergens may be substances produced within the body. They are called antiallergenic or autoallergens. They are natural – unmodified tissue proteins that are isolated from the systems that are responsible for immunity. And purchased – proteins that acquire foreign properties against thermal, radiation, chemical, bacterial, viral, and other factors. For example, an allergic reaction develops with glomerulonephritis, rheumatism, arthritis, hypothyroidism.