Cold ulticaria (cold hives) are mainly an allergic reaction to cold stimuli. They cause hives or large red welts to form on any exposed skin. These welts can be itchy and swollen. The disorder is classified as chronic as it can cause the appearance of hives for periods longer than 6 months, and sometimes for a whole lifetime. Nonetheless 30% of people affected do not have any more symptoms after 5 or 10 years.
Although the extent to which people react to cold is entirely personal, symptoms range from mild redness to severe reactions such as gastrointestinal pain, shortness of breath and rapid and irregular breathing. The most common cause of systemic reactions is swimming in cold water. A systemic reaction is not restricted to just causing welts, as other symptoms can include low blood pressure, fainting, shock and even death.
There are two main types of cold urticaria: the familial type, which can be inherited; and the acquired type, which occurs unrelated to the disease status of the relatives. The acquired form is seen most often in the late teens to mid twenties, although it can occur to younger children as well. Depending on the type, it can be stimulated by contact with cold objects and rainy/windy weather. This is also the type that can lead to death if a patient swims in cold water. Secondary cold urticaria has an underlying blood condition or infectious disease such as chickenpox, viral hepatitis and infectious mononucleosis which causes it; however this type is very rare.
“Depending on the type, it can be stimulated by contact with cold objects and rainy/windy weather”
The familial type on the other hand is a whole other beast, and has been considered a completely different disorder for a number of years. Familial cold autoinflammatory syndrome (FCAS) is an inherited disorder which causes rashes, conjunctivitis, fever/chills and joint pain in the exposure to cold objects and low temperatures (sometimes as high as 22°C). It is relatively rare with a prevalence of 1 per million people, and it is most common in Americans and Europeans.
Treatment for acquired cold urticaria, like many allergies, relies heavily on the use of antihistamines and avoiding the stimulus, in this case cold air and water. FCAS also requires the injection of immunosuppressants and monoclonal antibodies.