Q: In a hot humid, stuffy and warm weather my skin starts to itch like needles pricking. This happens mostly on the stomach and the back. There is no redness and the skin appears normal but the feeling is unbearable. It is ruining my whole life as I am on the move often. I have tried different lotions but it didn't work. I do not see it as a condition of hives as I tried medication for hives but it didn't work. Please tell me the cause of my problem and what can I do to solve it?

A:You could be suffering from cholinergic urticaria - although lack of skin lesions is rare. Cholinergic urticaria is a very common form of hives. It manifests as multiple, small, 2 to 3 mm red hives on the upper trunk and arms, although it can occur from the neck to the thighs. These hives appear in response to a rise in body temperature from exercise, overheating, or stress. Usually the hives develop within 2 to 20 minutes after the body temperature rises, although they can take up to an hour to occur. They cause itching, tingling, burning, and warmth of the skin. The hives last for minutes to hours with an average of 30 minutes. It is believed that histamine is released in response to stimulation by the parasympathetic nervous system. Many times the patient is asked to exercise by jogging in place or riding a stationary bike and the time it takes for hives to develop is noted. Cholinergic urticaria can be treated by limiting strenuous exercise. It responds well to a medication called hydroxyzine, which is an antihistamine. However, the main side effect of sleepiness is often not tolerated well. Showering with hot water may cause a release of histamine throughout the body depleting histamine stores and causing a 24-hour refractory period. It is worthwhile considering adrenergic urticaria as another possibility.