Urticaria, more commonly referred to as hives, consist of welts or swelling of the skin due to exposure to certain stimuli. Once exposed, the mast cells of the skin release excessive amounts of histamine. This release causes swelling all over the body. Though this condition does not leave permanent marks on the skin, and usually disappears in time without treatment, hives can still be an itchy and uncomfortable experience. Hives can be caused by a variety of different triggers.
Food allergens are one of the most common causes of hives. Commonly, these foods include chocolate, shellfish, nuts, milk and food additives called salicylates. Food-related hives are usually relieved upon taking allergy medications such as histamine-blockers.
Certain infections can also cause a breakout of hives. These infections include bacterial, fungal and viral infections (such as hepatitis). For children, it is not uncommon for even the common cold to produce a breakout of hives.
Most prescription, and many over-the-counter medications, also have the capability to produce hives when introduced into the system of sensitive individuals. According to the Mayo Clinic, aspirin, ibuprofen and penicillin are the medications that most commonly cause hives.
Allergies are probably the most common reason why a breakout of hives may occur. Even small specks of allergens such as dust, peanuts, pollen or ragweed can cause hives to develop in those individuals who are allergic to them. All allergens have the capability to produce hives. The severity of the outbreak is directly related to how sensitive the individual is to the allergen.
Hives can also commonly be caused by physical interaction with the environment. For example, the sun is a common cause of hives in some individuals. Extreme temperature changes, whether they be hot or cold, can also cause hives to occur. Even emotional stress can cause hives, especially during panic attacks.