An acute urticarial rash that spreads rapidly over the whole body is known as acute urticaria or hives. It involves itchy, raised red or pale bumps (wheals) that appear suddenly, are often temporary, and can be triggered by various factors such as foods, medications, infections, and physical factors like pressure or heat. While often mild, severe cases can involve angioedema (swelling) and respiratory symptoms, requiring immediate medical attention. Treatment typically involves over-the-counter