Hives, also known as urticaria is a skin rash usually as an allergy to food, medicine, or other irritants. This is a common condition  that is easily self-diagnosable and treatable. This condition is usually short-term, lasting between a few days or weeks.
Eating foods that the body is allergic to triggers the production of a chemical called histamine into the blood. This chemical works to protect the body against the invader and may cause hives; however, it can trigger swelling, redness, and itchiness of the skin.
Causes of Hives
Common triggers of hives include pollen, medication, foods, insect bites, environmental factors, animal dander, insect bites, and tight clothes.
Environmental factors like temperature changes can trigger urticaria in some persons who are sensitive to such temperatures. Coldwater, harmattan, or snow can trigger hives in some people, while direct, body heat or excessive sweating can cause heat-induced hives.
Urticaria is usually mild, and symptoms may improve on their own or with medication. In some cases, the symptoms can be chronic, accompanied by breathing difficulties, nausea, vomiting, severe swelling, and lightheadedness. Hives can be caused  by underlying health conditions, such as: