You may be a kind of cholinergic urticaria, cholinergic urticaria, belongs to what is often called rubella block in a kind. When heat, nervousness, intake of hot food or drink, or after exercise, the body temperature increases slightly, increase the heat cholinergic urticaria blood flow stimulation of the brain thermoregulation center, excitation of cholinergic nerves and the release of acetylcholine, if the chemical is allergic to this chemical, allergic reactions can occur. In addition to the absence of a rash and the sensation of pins and needles and severe itching, this type of allergic reaction can also appear in the trunk and proximal skin of the limbs (except armpits and palmoplantars), red, 2 mm or so, the wind, which is quick to come and go without leaving a trace. Mild cholinergic urticaria[2] can occur in the usual adolescent, usually after the cessation of exercise or calm, the symptoms can subside, so it is not easy to pay attention to. The specific situation can check the introduction of such diseases, or go to the hospital to check, or consult