How does skin itch scratch to rise a knot to do

Skin itching a scratch on the pimple, should be artificial urticaria, also known as physical urticaria, mechanical urticaria. Patients in the process of scratching the skin, subcutaneous blood vessels by this mechanical stimulation, mast cells will release histamine, causing vasodilation, thus causing skin itching. The treatment of artificial urticaria is relatively simple. It is recommended to take oral antihistamines with the knowledge of a doctor, such as desloratadine, loratadine, chlorpheniramine, ebastine, epinastine, mizolastine, levocetirizine, etc. However, if the symptoms are mild, don't worry about it, it will be better in ten minutes. The allergen of artificial urticaria is mechanical stimulation, all drugs are symptomatic treatment, there is no cure, but some people will gradually reduce or heal after a few years.