Hives symptoms and causes
Medically known as urticaria, hives are the itchy red welts that develop as a result of reactions to foods and other provoking substances. For example, certain medications—aspirin, as well as penicillin and related antibiotics—can cause hives in some people. Even those without known allergies can develop hives after being stung by an insect or touching stinging plants, such as nettles, poison oak, or poison ivy. Hives may be accompanied by other symptoms of allergy, including swelling of the eyes and other parts of the body. Many food allergies provoke swelling and itching of the lips and mouth. Warning: If hives are accompanied by swelling of the throat and difficulty breathing, speaking, or swallowing, seek immediate medical help. These symptoms may signal anaphylaxis, a potentially fatal medical emergency.
