Hives occur when the immune system responds abnormally to a substance, disease, or environmental condition, triggering the release of a chemical called histamine into the bloodstream. This causes blood vessels to dilate and leak fluid into the middle layers of skin. Hives (medically known as urticaria) appear on the skin as welts that are red, very itchy, smoothly elevated areas often with a blanched center. They appear in varying shapes and sizes, from a few millimeters to several centimeters in diameter anywhere on the body. The main symptom of hives is an itchy rash. The rash can: Hives rash on the leg and hand of a child with white skin. The skin on most of their thigh is pink, raised and bumpy. At the side of their thigh, close to their hand, are deep creases in the skin. Hives, also known as urticaria, is a kind of skin rash with red or flesh-colored, raised, itchy bumps. [1]. Hives may burn or sting. [2]. The patches of rash may appear on different body parts, [2] with variable duration from minutes to days, and typically do not leave any long-lasting skin change. [2]. Hives (urticaria) is a rash often triggered by allergens or irritants. Home remedies like cold compresses, oatmeal baths, and keeping cool may help relieve itching and swelling. Hives are itchy, raised bumps or welts that come and go on your skin. They’re most often red or skin-toned, but can look different depending on the color of your skin. They can be as small as a pencil eraser or as large as a dinner plate. Sometimes, you can also experience swelling deeper in your skin (angioedema). Hives are common. Hives, also known as urticaria, affect about 20 percent of people at some time during their lives. It can be triggered by many substances or situations and usually starts as an itchy patch of skin that turns into swollen red welts. Hives, also known as urticaria, are itchy, raised welts that are found on the skin. They’re usually red, pink, or flesh colored on lighter skin and may be flesh colored or slightly lighter or. Hives — also known as urticaria (ur-tih-KAR-e-uh) — is a skin reaction that causes itchy welts that range in size from small spots to large blotches. Hives can be triggered by many situations and substances, including certain foods and medications. Angioedema can arise with hives or alone. Urticaria, also known as hives, is an outbreak of pale red or discolored bumps or welts on the skin that appear suddenly. The swelling that often comes with hives is called angioedema. Allergic.