Cold urticaria occurs in two forms. The rare form is hereditary and manifests as hives all over the body 9 to 18 hours after cold exposure. The common form of cold urticaria presents with the rapid onset of hives on the face, neck, or hands after exposure to cold.
Cold urticaria is common and lasts for an average of 5 to 6 years. The population most affected is young adults age 18 to 25 years. Many people with cold urticaria also have dermographism and cholinergic urticaria.
Severe reactions can be seen with exposure to cold water. Swimming in cold water is the most common cause of a severe reaction. This can cause a massive release of histamine resulting in low blood pressure, fainting, shock, and even death.
Cold urticaria is diagnosed by holding an ice cube against the skin of the forearm for 1 to 5 minutes. A distinct hive should develop if a patient has cold urticaria. This is different than the normal redness that would be seen in people without cold urticaria.
Patients with cold urticaria should learn to protect themselves from a rapid drop in body temperature. Regular antihistamines are not generally effective. The antihistamine cyproheptadine (Periactin) has been found to be a useful treatment. The tricyclic antidepressant doxepin has also been found to be an effective blocker of histamine release. Finally, a medication called ketotifen, which keeps mast cells from releasing histamine, has also been used with success.