Urticaria is basically an allergic reaction. First we need to try to identify the trigger. Sometimes, even with extensive search on enquiry to find the trigger one might not succeed, many doctors prefer to do autologous serum testing because in some cases patients develop allergy to some antigen in their own serum and with repeated injections this sensitivity can be subdued. When no cause is detected, in such cases of Idiopathic urticaria need to continue with medicines to keep the allergic response subsided. Febucip (fexofenadine) and Deslor (desloratidine) are pretty safe medications even on long term use. Hope this helped.