Allergy to cold weather?
No, I’m not referring to snowbirds who leave the northern states to winter in Arizona, Texas or Florida. I’m referring to the development of hives after you have been exposed to cold temperatures.
Cold-induced urticaria (hives) is a type of physical urticaria. Other physical triggers are heat, vibration, solar, pressure and aquagenic. For cold-induced urticaria, I have seen patients who developed hives on the soles of their feet after walking barefoot on cold grass in the early morning or hives on their arms after having cold water running down their arms from a leaky hose. Sometimes, just holding a cold can of your favorite beverage long enough can result in hives on the palm of your hand. Coming into the lodge after snow skiing can result in facial hives if that ski mask and scarf were left in the car.
The reason cold-induced urticaria occurs is thought to be related to cold-sensitive proteins in the blood/skin tissues that result in histamine release from Mast cells. The release of histamine leads to the formation of hives.
Is there a test to confirm cold-induced urticaria? For the most common type of cold-induced hives called idiopathic cold urticaria, the ice cube test is diagnostic. That’s right, an ice cube is placed on the forearm for several minutes and as the skin re-warms, hives develop at the site where the ice cube was placed.
There are several unusual forms of cold-induced urticaria where the ice cube test is negative. One form is an inherited (Familial Cold urticaria) where symptoms are delayed and include flu-like symptoms.
How do you treat cold-induced urticaria? The best treatment is to avoid extreme cold temperatures. This includes wearing warm clothing, hat, gloves, etc to stay warm. Antihistamines can also be effective for treatment. Newer generation antihistamines are generally preferred because they are as effective as Benadryl but have fewer side effects.
Can cold-induced urticaria be dangerous? In most cases, cold-induced hives is simply a nuisance. However, submersion in cold water could lead to a massive release of histamine leading to anaphylaxis with low blood pressure. For this reason, persons with cold-induced urticaria should not swim alone and should keep self-injectable epinephrine (EpiPen) available. So, avoid the “polar bear plunge”!
If you have cold-induced urticaria (hives) don’t move south, call your allergist.