Little red dot is itchy when it is hot, but it will disappear automatically after cooling for a period of time. I don't know what's going on.

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

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

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

Urticaria has urticaria vulgaris,

Vascular edema, artificial urticaria, solar urticaria, cold urticaria, cholinergic urticaria and other types. The treatment is the same.

But according to the above reasons, it is better to avoid it.