It is essential to rule out the presence of serious illnesses of which recurring hives can be a symptom.
Examples are hepatitis, hyperthyroidism, lymphomas, collagen vascular diseases, and cancers of the rectum, kidneys and gastrointestinal tract. Chronic infections such as chronic sinusitis can be associated with urticaria.
Causes of urticaria include Drugs and Chemicals, contactants, certain foods, infections and systemic diseases.
Have these systemic diseases being ruled out in your case?