The immune system is designed to protect the body against invasion by harmful foreign bodies. Allergies happen when your body has an immunological reaction to a foreign substance that doesn’t normally trigger an immune response in most people. This could be some types of food, pollen, sawdust, insect venom, shellfish, anything.
Antibodies produced by the immune system tag these normally harmless substances as allergens. The immune system’s reaction to these allergens can cause an inflammation of the sinuses, windpipe, skin or digestive system.
According to the American Academy of Allergy, Asthma and Immunology , up to 50 million people living in the United States have an allergic disease. People have allergic reactions to different things, and the severity varies from person to person. They could be as minor as temporary rashes or as life-threatening as an anaphylactic shock.
An allergic reaction doesn’t look the same on anyone. If you experience any of these symptoms in response to a foreign substance, it may a sign you’re allergic to it.