What reason is skin itch to rise a knot

Skin itching is considered to be a symptom of urticaria, also known as urticaria mass, is a kind of swelling limited to the skin, mucosal surface edema mass, accompanied by different degrees of itching, some patients will also show vascular edema, will occur at any age stage. It is divided into artificial urticaria, contact urticaria, pressure urticaria, solar urticaria, water urticaria, cholinergic urticaria. It is mainly caused by contact with allergic food or virus infection, as well as local friction, pressure or exposure to hot and cold light. Symptoms can be seen in regular hospitals for detailed examination, under the guidance of doctors, symptomatic use of drugs according to the severity of the disease.