What are Hives?

Hives are red, itchy welts on the skin that come and go over the course of minutes or hours. All types of hives can cause itching. They usually form on the skin but sometimes also in the soft tissues of the mouth, eyes and throat.

Many substances can trigger hives, including animal dander (especially cats), insect bites, medications, pollen and shellfish, fish, nuts, eggs, milk, and other foods.