Cold urticaria (ur-tih-KAR-e-uh) is a skin reaction to cold. Skin that has been in contact with cold develops reddish, itchy welts (hives).
The severity of cold urticaria symptoms varies widely. Some people have minor reactions to cold, while others have severe reactions. Swimming in cold water is the most common cause of a whole-body (systemic) reaction. This could lead to very low blood pressure, fainting, shock and even death.
Cold urticaria occurs most frequently in young adults. And it generally clears up within a few years. If you think you have this condition, consult your doctor. Treatment for cold urticaria usually includes taking antihistamines and avoiding cold air and water.