Itchy eyes and a runny nose are not the only reaction that allergens can cause. Urticaria (also known as hives) is an inflammation of the skin, which is triggered when the immune system releases histamine. The histamine causes blood vessels to leak, and the skin to swell. This can leave you with itchy, red and white bumps or welts that range in size and can appear anywhere on the body.
Two types of uticaria exist:
- Acute urticaria can occur upon eating specific food or coming into contact with a trigger. It can also result from other factors such as heat, exercise, medication reactions or insects.
- Chronic urticaria is an ongoing reaction that could be caused by many different triggers. It can last for years.
The good news is that although these hives can be uncomfortable or even painful, they are not contagious and can often be minimized and treated.