What is an allergy

Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to something in the environment that usually causes little or no problem in most people. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis

Symptoms may include red eyes, an itchy rash, sneezing, a runny nose, shortness of breath, or swelling.Food intolerances and food poisoning are separate conditions

Common allergens include pollen and certain food.Metals and other substances may also cause problems. Food, insect stings, and medications are common causes of severe reactions