Urticaria is not too much internal toxicity, internal toxicity belongs to the folk concept and has no scientific basis. Urticaria is caused by some allergies and other factors, mast cells as the core of a variety of inflammatory cell activation, at the same time will release some chemical mediators, resulting in vasodilation and vascular permeability increases, smooth muscle contraction and increased secretion of glands appeared systemic allergy symptoms. The common cause of urticaria is allergy, such as contact with allergic foods, drugs, respiratory tract inhalation and skin contact, but also with some physical factors, and mental, endocrine factors, and endotoxicity does not have much to do. Urticaria should go to the hospital in time, this disease can be clinically cured, but easy to recur, most patients do not leave traces after the rash subsides, and some cases can be self-cured after removing the cause of the disease. Diagnosed with urticaria, should be timely medical treatment, according to the condition of the treatment, do not private treatment, to avoid aggravation of the disease.