Hives

Hives, or urticaria, are often triggered by an allergic reaction in the body that causes it to release histamine (a protein). When histamine is released, capillaries in the body leak fluid which collects under the skin and creates the resulting red & elevated (often itchy) rash.

The raised or swelling of the skin is called wheals and these are usually somewhat round and pink or red. The wheals can be as small as a few millimeters to a number of inches wide. Most commonly hives appear on the face or legs, feet, arms, etc.).

Common causes of hives can be insect stings/bites, foods, medicines, sun, parasites, latex, chemicals, and exposure to extreme temperatures (high or low). Since they are an allergic reaction, hives are not contagious and it can often be difficult to determine their cause.

There are two types of hives based on the length of the symptoms. If hives last for less than six weeks, they are considered acute hives. These are the most common type of hives and luckily, most cases last for less than 24 hours. If symptoms persist for more than six weeks, they are considered chronic hives.