You may have cold urticaria, an extreme reaction to cold. People with this condition have mast cells in the skin that release histamine and other chemicals when exposed to cold. In rare cases, cold urticaria is genetic or associated with a disease such as hepatitis or cancer. When temperatures plunge (typically below 39°F), people with urticaria can break out in hives (itchy, reddish welts) on areas of exposed skin. Symptoms can occur at a wide range of temperatures, and humidity and wind chill factors are important variables. Sipping an icy drink or eating ice cream can cause the lips or throat to swell in some people with the condition. In severe cases, cold urticaria can trigger anaphylaxis, a serious allergic reaction that can lead to shock, trouble breathing or swallowing, and even death. For example, swimming in cold water can lead to death from anaphylaxis.
To protect yourself, when it’s cold outside, bundle up and leave as little skin exposed as possible. Also avoid contact with cold objects, cold food and drinks, and swimming in water below 77°F. Alert your health-care providers as well, as cold IV fluids or surgical procedures can cause an episode.
If these steps don’t help, take an over-the-counter (OTC) antihistamine such as loratadine (Claritin) when temperatures dip. A doctor might prescribe cimetidine (Tagamet), an acid reducer that is also used as an antihistamine, the anti-inflammatory drug omalizumab (Xolair), or epinephrine (EpiPen), an injection used to treat severe allergic reactions.
Urticaria can be a lifelong condition, but studies show that symptoms go away after about five years for about half of those with this condition.