Acute urticaria is usually caused by two types of factors, one is allergic and the other is infectious. The main allergic factors are food, medications, and contacts. Infectious factors are mainly bacterial infections, viral infections and parasitic infections. If the hives are caused by allergic factors, they will heal in about 1-3 days after removing the allergen; if the condition does not improve after removing the allergen, add a little anti-allergic drugs, such as loratadine, cetirizine, epinephrine, etc., and they will usually get better naturally in about 3-5 days. However, if the infective urticaria is caused by bacteria, the addition of antibiotics and anti-allergic drugs will provide relief in about 3 days and complete healing in about a week; if it is a viral infection, the cycle of viral infection is usually a week; parasitic infection, after removing the parasitic infection, can also heal itself more quickly.