If the exposure to cold is over large areas of the body, large amounts of histamine may be released which can produce wheezing, flushing, generalised hives and fainting. Cholinergic urticaria is tiny bumps surrounded by a white or red halo which come on with exercise, heat or emotion. These bumps itch intensely. Anything which raises the skin temperature can cause these tiny hives - sweating, sunlight, hot baths, blushing or anger. The most common of the physical urticarias is called Dermatographism .
Hives form from firmly stroking or scratching the skin.
These hives may be very itchy. The ideal treatment for hives is to determine cause and then eliminate it. Unfortunately, this is not always an easy task. While investigating the cause of hives, or when a cause cannot be found, antihistamines are usually prescribed by your dermatologist to provide some relief. Antihistamines work best if taken on a regular schedule to prevent hives from forming.