This clinical trial is focused on studying the treatment of acute urticaria, a condition characterized by sudden outbreaks of red, itchy welts on the skin, often accompanied by swelling known as angioedema. The study is being conducted in emergency departments and involves adult patients who experience this condition. The treatment being tested includes the use of a medication called prednisone, which is a type of corticosteroid, in combination with an antihistamine. A placebo is also used in the study for comparison purposes.

The purpose of the study is to determine if using just an antihistamine is as effective as using both an antihistamine and a corticosteroid like prednisone in treating acute urticaria. Participants in the study will receive either the combination of medications or the antihistamine alone. The study will monitor the effectiveness of these treatments over a period of time, with a focus on the symptoms experienced by the patients.

Throughout the study, the progress of the participants will be tracked to assess the severity of their urticaria symptoms. This will help researchers understand the best approach to managing acute urticaria in emergency settings, potentially leading to improved treatment strategies for patients experiencing this condition.