Cold urticaria

Cold urticaria (essentially meaning "cold hives") is an allergy where hives (urticaria) or large red welts form on the skin after exposure to a cold stimulus. The welts are usually itchy and often the hands and feet will become itchy and swollen as well. Hives vary in size from about 7mm in diameter to as big as about 27mm diameter or larger. The disease is classified as chronic when hives appear for longer than 6 weeks; they can last for life, though their course is often unpredictable. This disorder, or perhaps two disorders with the same clinical manifestations, can be inherited (familial cold urticaria) or acquired (primary acquired cold urticaria). The acquired form is most likely to occur between ages 18–25, although it can occur as early as 5 years old in some cases.