All dermatologists at the Skin Hospital are highly trained to treat this condition. Your specialist will ask you detailed questions to understand whether there are any obvious triggers for your hives. Often no tests are needed to confirm the diagnosis. Blood tests may sometimes be needed to look for underlying causes and to distinguish urticaria from other conditions (especially if wheals are present for over 24 hours at a time). A skin biopsy is not normally needed, but may be requested to rule out other causes.