An allergic reaction is a response by the immune system to a substance that it perceives as a threat. This substance, known as an allergen, can be a wide range of things, including foods, medications, insect venom, or environmental factors such as pollen or dust.

When the immune system encounters an allergen, it produces antibodies that cause the release of histamine and other chemicals, which trigger a range of symptoms. These symptoms can include itching, redness, swelling, hives, difficulty breathing, and in severe cases, anaphylaxis, which is a potentially life-threatening reaction that requires immediate medical attention.

Treatment for an allergic reaction typically involves identifying and avoiding the allergen. Antihistamines and other medications may be used to relieve symptoms such as itching and swelling. In cases of severe allergic reactions, such as anaphylaxis, emergency treatment with epinephrine may be required.

It is important for individuals who have a known allergy to carry an epinephrine auto-injector with them at all times and to educate those around them on how to recognize and respond to a severe allergic reaction.

Preventing allergic reactions involves identifying and avoiding known allergens as much as possible. If you have a known allergy, it is important to read food and product labels carefully, avoid cross-contamination of foods, and take steps to reduce exposure to environmental allergens such as pollen or dust. In some cases, allergen immunotherapy may be recommended, which involves gradually exposing the immune system to small amounts of an allergen over time to desensitize it.