The immune system's reaction to a substance that it deems foreign is called an allergic reaction. The immune system produces antibodies to fight the foreign bodies called antigens. In the episode of an allergic reaction, the antibodies react against harmless substances. This overreaction causes symptoms such as rashes, a runny nose, nausea and diarrhea and even shortage of breath. If left untreated this mild condition can turn into a fatal condition. Food allergies, insect stings and medical allergies are some of the common causes.
HOW IS ALLERGIC REACTION DIAGNOSED?
In some cases, allergies cause fatal reactions called anaphylaxis.