By definition hives that continue to recur for greater than six weeks are considered chronic. Rarely is an identifiable etiology for the hives discovered. Because of the remote possibility of an underlying pathologic process, such as infection, abnormal thyroid gland function, malignancy or rheumatoid arthritis, a review of your health history and limited blood testing directed toward these entities is routine practice. Fortunately, most cases (~ 75%) resolve within one year. Therapy is symptomatic, aiming to reduce itching while the hives run their course.
How can hives be treated?
Avoidance of the foods, drugs, or other provoking factors is recommended whenever possible. Oral antihistamines, like Benadryl, are often used to treat recurrent episodes. When hives are chronic, or frequent, high doses of oral antihistamines are given daily.