Allergen

An allergen is any substance that, if ingested, can cause an allergic reaction—a hypersensitive state that stimulates the production of reaginic antibodies, and which may have sometimes severely negative medical impacts upon the individual. Allergens include viruses and bacteria, dust, pollen and smoke particles that may be inhaled, foodstuffs, and chemicals. The allergic reaction varies from individual to individual and from place to place, since the environmental quality of the air varies according to location and time.

The huge increase of chemical substances used in foodstuffs and other consumer products mean there are many more possibilities for allergic reactions. Consequently, advice on how to avoid allergens has become increasingly prevalent in modern society. This includes warnings on consumer products, public health warnings and, rather less reliably, ...