When acute urticaria subsides, it is usually necessary to continue taking antihistamines for a short period of time. But whether to take long-term medication to follow the doctor’s advice, according to the cause of acute urticaria to decide whether to continue to take medication, the causes include exogenous factors and endogenous factors. 1. Exogenous factors: exogenous factors may be related to diet, drugs, inhalation of allergens, mosquito bites and some physical factors, for these causes of acute urticaria eliminating the causes do not need to continue to take long-term medication. 2. Endogenous factors: for a variety of microbial infections or systemic diseases, such as diabetes mellitus, hyperthyroidism, renal disease, leukemia, etc., this situation can not eliminate the causative agent, the symptoms subside can not be long-term to eat to relieve itching medication, but can not stop eating drugs for the treatment of the underlying disease, the need to continue to take medication, to avoid recurrence. Acute urticaria during the medication should follow the doctor’s instructions to stop, can not blindly stop their own medication, to avoid recurrent episodes.