QUESTION

About a year ago, my wife started breaking out in hives when she didn’t dress properly in cold weather. What could be causing this?

ANSWER

Your wife may have a condition known as cold urticaria. People with this condition have an extreme reaction to cold. When temperatures plunge (typically below 39°F), these individuals can break out in hives (itchy, reddish welts) on areas of skin exposed to cold air. Temperature, humidity and windchill factor are important variables. Individuals with this disorder can have symptoms at a wide range of temperatures, and the higher the temperature that causes the symptoms, the more severe the disease tends to be.

In some people with cold urticaria, sipping an icy drink or eating ice cream can cause their lips or throat to swell. In severe cases, cold urticaria can trigger anaphylaxis, a serious allergic reaction that causes an over-release of chemicals that can lead to shock (a dramatic drop in blood pressure), fainting, trouble breathing or swallowing and even unconsciousness or death. Aquatic activities, especially swimming in cold water, can lead to death either from anaphylaxis or drowning as a result of the anaphylaxis.

What causes cold urticaria? People with this condition have mast cells (cells that play a key role in inducing allergic reactions) in the skin that release histamine and other chemicals when exposed to cold. No one knows what exactly causes the skin mast cells to be so sensitive, but there are a number of diseases associated with various forms of cold urticaria, and there are inherited/genetic forms that can manifest at a very young age.

To diagnose cold urticaria, many doctors rely on a simple test. An ice cube is placed on the forearm for five minutes. If this results in hives or swelling, a positive diagnosis is made.

To best protect herself, your wife should be sure to bundle up during cold weather, leaving as little skin exposed as possible. In addition, she should avoid contact with cold objects…forgo cold food and beverages…and swim in water that is above 77°F. Note: Your wife should inform health-care providers of the condition, as cold IV fluids or surgical procedures can cause an episode.

If these steps don’t prevent episodes of cold urticaria, she also can take an over-the-counter (OTC) antihistamine such as loratadine (Claritin) or cetirizine (Zyrtec) when temperatures dip or prophylactically before cold exposures. If OTC antihistamines don’t provide relief, doctors might prescribe medications such as cimetidine (Tagamet), an acid reducer that is also used as an antihistamine…the anti-inflammatory medication omalizumab (Xolair)…or epinephrine (EpiPen), an injection used to treat severe allergic reactions.

Even though cold urticaria can be a lifelong condition, your wife may be one of the lucky ones. Studies show that symptoms go away after about five years for about half of those with this condition.