Urticaria happens when your skin abnormally reacts to certain allergens giving rise to rash. These allergens can be present in your environment or in your blood. Many times its difficult to pin point exact allergen. As such there is no "cure" for urticaria. Medicines like levocetrizine and in severe cases steroids for short term help to "control" this allergy. For best results a continuous treatment may be necessary.. avoid taking medicines on sos basis. However if these medicines are not effective then advanced medicines like biologicals, cyclosporine etc help achieve long term control. Also autologous serum therapy may be tried. Talk to your dermatologist about these treatments, whether they will be suitable in your case. Blood allergy test is ambiguous in most cases. Just because your test may show you allergic to something doesn't mean that avoiding it will make your skin disease free. However if you wish to undergo it you can ask your doctor for details about it. Hope this helps. Warm regards Dr Pinanky Jadhav Eternis clinic, Pune