After going for a run or attending a yoga class have you ever noticed red, sometimes itchy bumps on your skin? No, you’re not allergic to exercise, but you could be breaking out in hives. Physical urticarial, also known as hives caused by the direct stimulation of the skin, occur where skin has been irritated. This could be caused from a wide variety of factors including cold, heat, sun exposure, vibration pressure, sweating and exercise, and usually appear within one hour after exposure or irritation. An easy way to tell that your skin is experiencing physical urticarial, is if the hives only appear on skin that has been exposed or stimulated by said irritants.
What are hives? They’re not dangerous, but they are a reaction. Hives are actually the result of blood plasma that leaks out of small blood vessels in the skin. Allergic reactions from sunlight exposure, insect stings or bites, chemicals from certain foods, or medications cause histamine release from specialized skin cells. The histamine in turn, prompt blood plasma to release and form the red blotches and itchy marks found along the skin.
So, next time you go for a run and your arms rub against your sides or your legs chafe on the gym’s elliptical and you find yourself red and blotchy afterwards; know that it’s a normal reaction experienced by many fellow exercisers. However, it’s important that your dermatologist evaluates any new mark, blemish or bump in order to determine exactly why your skin is reacting that way.
Besides exercise, there are other reasons for your skin to develop hives. Dermatographism, for example, are hives that form in reaction to harsh rubbing or scratching of the skin. It’s not unusual for a patient to experience other forms of hives, if they experience dermatographism.
Sometimes the solution isn’t as simple as stopping the scratching or avoiding irritants. Hereditary angioedema is a painful swelling of tissue that’s passed through families.
The two different type of hives are acute urticarial, which is when swelling lasts less than six weeks or chronic urticarial, which is swelling that lasts more than six weeks. The most common causes are foods, medicines, latex, or infections. Insect bites and internal disease may also be responsible. The most common foods that cause hives are nuts, chocolate, fish, tomatoes, eggs, fresh berries, soy, wheat, and milk. Fresh foods cause hives more often than cooked foods, and it is thought that certain food additives and preservatives may also be to blame.
Chronic urticarial is usually more difficult to identify than those causing acute urticaria because the causes can be similar to those of acute urticaria but can also include autoimmunity, chronic infections, hormonal disorders, and malignancy.