Cholinergic urticaria is more common in young people. It is mainly caused by the rise of body deep temperature after exercise, heat, emotional tension, hot drinks or alcohol drinks, which promotes acetylcholine to act on mast cells. It shows that there is a wheal a few minutes after being stimulated, with a diameter of 2-3 mm, and a red halo of about 1-2 cm around. It often emanates from the upper part of the trunk and upper limbs, and does not fuse with each other. It is conscious of severe itching. Sometimes there is only severe itching without skin damage, and it can subside within 0.5 to 1 hours. Occasionally accompanied by systemic symptoms caused by acetylcholine, such as salivation, headache, weak pulse, narrowed pupils, spastic abdominal pain, diarrhea, etc., severe dizziness can cause syncope. When 1:5000 acetylcholine is used for acupuncture or scratch test, wind masses can appear at the injection site, and satellite like small wind masses can appear around.
