Urticaria is a temporary restrictive edema due to dilation and increased permeability of small blood vessels in the skin mucosa. It manifests as pruritic erythematous and windy patches, and some severe patients may have systemic manifestations such as abdominal pain, vomiting, chest tightness, and respiratory distress. The etiology is complex and most patients have difficulty finding a very precise cause. The possible causes of urticaria are: 1, biological: food (fish, shrimp, eggs are common), inhalants (pollen, dust, mold spores, etc.), infectious agents (bacteria, viruses, parasites, etc.); 2, chemical: daily chemical products chemicals, etc.; 3, physical: temperature, light, etc.; 4, pharmacological: antibiotics, antipyretic and analgesic drugs, etc.; 5, endogenous: mental factors, genetic factors, etc. Principles of urticaria treatment: remove the cause, stop the itching, eliminate the lesions and accompanying symptoms. Antihistamine, anti-inflammatory, capillary permeability reduction and symptomatic treatment are the main drugs, combined with topical topical medication when necessary.