They say cold weather can bring out the worst in you but none are more aware of this than people who suffer from cold induced hives. Cold urticaria (CU) is the medical term for "cold-induced hives" or welts. CU represents a small subgroup of people that experience chronic urticaria. About one in five people will at some point in their life have an episode of hives. One percent of the population may have hives with or without swelling that lasts for six or more weeks, which means it is** chronic**.
Cold urticaria occurs when cold exposure results in the development of small or large areas of raised, itchy skin. The raised portion may have a lighter hue, but it's often surrounded by reddened areas of skin. Hives can occur on any part of the body, but in the case of CU, they typically occur on the cold exposed areas of the skin. Many patients develop hives and swelling soon after contacting cold air or water. Eruptions commonly occur on the face, neck, ears, arms, hands, legs and feet. The eye lids and lips may swell so severely that vision or speech is impaired.
Holding a cold can or bottle of soda may result in itching and swelling. Shoveling snow may be associated with hives and swelling of the exposed areas of the body. Drinking an ice cold beverage may be followed by swelling of the tongue or throat, which can be fatal if severe.
If a person who has CU jumps into a cold swimming pool, lake or pond, life threatening anaphylaxis may follow. The resulting abrupt release of histamine and other substances which occurs in an allergic reaction may cause, all at once, many blood vessels to dilate, and subsequently drop the blood pressure to a dangerously low level (vascular shock). Furthermore, the distress from this experience may cause drowning.
How is Cold Urticaria diagnosed?
Allergists are trained to diagnose and treat CU. An ice cube test is usually done to confirm the diagnosis. This involves placing a small ice cube on the arm for 5 minutes and reassessing 10 minutes after it has been removed. When the skin reddens and forms bumps or a welt the test is positive. Often the rewarming of the skin after the cold contact leads to the skin rash.
Sometimes blood tests are ordered to rule out an underlying immunological, autoimmune or other blood related disorder. This is why it is important to see a doctor if you have hives, even if very mild. Additionally, ask family members, aunts, uncles, cousins and grandparents whether they have ever had hives or chronic swelling. There are some familial types of CU which may require further investigation.
How is Cold Urticaria treated?Unfortunately there is no cure for CU. The good news is that treatment is usually successful, meaning skin eruptions are suppressed. Avoiding contact with cold water, air or objects is crucial. Your doctor will select a long acting antihistamine to be used either regularly or when anticipating a high risk event (such as shoveling snow, or swimming). Patients are invariably cautioned never to jump or dive into cold water under any circumstances. If further testing identifies an underlying process (mentioned above) other special treatments may be required.
Cold urticaria is a treatable disorder that may be successfully controlled after appropriate evaluation by an allergist and advisory on avoidance and treatment.
The Journal of Allergy and Clinical Immunology, Pages 1415-18, June 2006