Urticaria is a very common skin disease that causes an extremely itchy, swollen rash on the skin, like a mosquito bite, which can subside on its own but often occurs repeatedly and comes and goes like the wind. It can occur at any age, and about 20% of people experience hives at least once in their lifetime. Such skin bumps …… are caused by dilated blood vessels in the skin and increased permeability. Sometimes the swelling of the skin thickens when the phenomenon is located deeper in the blood vessels, also known as “angioneurotic edema”, and is common on the lips, eyelids, and palms of the hands and feet. If it unfortunately occurs in the throat, the patient may experience chest tightness, difficulty breathing, and in severe cases, even life-threatening symptoms. The rash will usually clear up within 24 hours, but it can recur if exposure to the allergen is not stopped. Although the hives will disappear within 24 hours, this does not mean that there is no allergy, but only that they appear in a different place, and the area where the rash appears will keep changing throughout the body. The symptoms of urticaria are classified as acute or chronic according to the duration and frequency of the attacks. symptoms that appear within 6 weeks are acute attacks, with an acute incidence of about 15-20%; if the symptoms are repeated for more than 6 weeks, the symptoms are chronic urticaria. If the body is exposed to one or more allergens, including ingestion, inhalation, skin contact, or injection into the body, it can cause skin urticaria. Most of the causes of acute urticaria are related to food allergies and drug allergies. Statistically, food allergies are more common, followed by drug allergies, but there are also other causes of allergy, including infections, inhalant allergens, endocrine and other physical factors.