As soon as the weather is hot or the mood is excited, little red dot appears on my body, and it itches and disappears in about a few minutes. What's the matter?

This is a special type of urticaria, called cholinergic urticaria.

It belongs to a kind of "rash" that people often say. When heated, nervous, eating spicy and hot food or drink, or after exercise, the body temperature increases slightly, and the heated blood flow stimulates the brain thermoregulatory center, excites cholinergic nerves and releases acetylcholine. If you are allergic to this chemical, you can have an allergic reaction.

This kind of allergic reaction has no rash, only acupuncture and severe itching, and red "wind masses" of about 2 mm can also appear on the skin of trunk and proximal limbs (except armpits and palms and soles). This kind of wind mass comes quickly and leaves no trace. Mild cholinergic urticaria can occur in adolescence of ordinary people. Generally, after stopping exercise or calming down, the symptoms can subside, so it is not easy to attract attention. The whole process can range from months to years, and those with frequent attacks should go to dermatology for diagnosis and treatment in time. After treatment with antihistamines and anticholinergic drugs, the condition can be alleviated or alleviated.