Take antihistamine medicine to reduce the allergic response. Some allergic reactions are emergencies. Once the emergency symptoms have been treated you will be instructed in medication to take for the next several hours to days to prevent the reaction from recurring. These severe allergic reactions can be life-threatening and require immediate medical treatment. Any one hive will eventually clear without treatment, but taking drugs such as antihistamines or corticosteroids help the hives go away faster, treat the itch, and prevent new hive formation.
Chronic hives come and go for a long time.
Most often, it is not possible to determine their cause. Antihistamines are usually helpful. The hives may resolve spontaneously after weeks or months but may recur off and on. Call 911 at once if you have an allergic response that affects your breathing. Call your doctorl if you have frequent outbreaks of hives.