No one likes being cold, but some people can actually be allergic to chilly temperatures, breaking out in a rash or even suffering a potentially life-threatening reaction when exposed to cool air or water.
Cold urticaria is a rare condition that can be confirmed with an “ice cube test.”
A recent report in The Journal of Emergency Medicine described the case of a 34-year-old man in Colorado who collapsed after stepping out of a hot shower into a cold bathroom. His family found him lying on the floor, covered in hives and having trouble breathing.
He was rushed to the emergency room of a local hospital, where doctors found him to be in anaphylactic shock — a severe allergic reaction — with dangerously low blood pressure and shortness of breath. Emergency physicians are used to seeing this reaction with people who are allergic to peanuts or insect stings, but they should be aware that cold temperature alone may also trigger anaphylaxis, the authors wrote.
The patient’s family told the hospital the man had a history of being “allergic to the cold weather” and had several episodes since moving to Colorado. He improved after receiving epinephrine, oxygen and other treatment.
An ice cube test — the simplest way to diagnose cold urticaria — confirmed he had the condition. Doctors place ice on a patient's skin for about five minutes to see if he or she develops welts in that spot, even after the ice is removed and the skin starts to warm up.
The man was “counseled” about avoiding cold water and other cold situations, prescribed an epinephrine auto-injector and discharged from the hospital feeling fine.
What is cold urticaria?
It’s an allergic condition that affects the skin when it's exposed to cold, according to the Genetic and Rare Diseases Information Center. Symptoms usually begin in young adulthood and the most common sign is a red, itchy rash after cold exposure.
That could mean being outdoors on a chilly day, jumping into a cold pool or even sitting near air conditioning, said Dr. Adam Friedman, professor and interim chair of dermatology at the George Washington School of Medicine and Health Sciences in Washington, D.C.
“It can be very disruptive when not managed and if the environment is not ‘friendly,’ meaning cold. I have had patients move to warmer environments, but they are still at risk,” Friedman told TODAY.
One woman he treated had to fight to get a space heater at work because the company worried about the potential fire hazard.
Cold urticaria is different than just having rosy cheeks in the winter since this condition involves a histamine response, which has an effect on the blood vessels and sensory nerves — giving the feeling of itching and burning, Friedman said.
It's also different from Raynaud's disease, where cold temperatures cause blood vessels to constrict, turning fingers and toes white.
What are the symptoms?
They can include a red rash, swelling and headache, which appear minutes after exposure to cold and usually resolve soon after. Affected people who come to see Friedman during the fall and winter often have hives when they walk in the door, which disappear as soon as they rewarm
But the symptoms can last for up to two hours in some patients and include a severe, life-threatening allergic reaction. A massive histamine release could lead to trouble breathing, shock or passing out.
What causes cold urticaria?
It’s unknown, though some cases are triggered by an infectious disease, an insect bite, certain medications or blood cancer, the Genetic and Rare Diseases Information Center noted.
The case report called the condition “uncommon, or perhaps underdiagnosed.” The incidence in estimated to be 0.05% of the population.
In some people, cold urticaria simply goes away after several years.
What is the treatment?
The main way is to avoid being cold, whether by wearing the appropriate winter clothing, not staying outdoors too long on chilly days, and skipping cold showers and cool pools.
Patients can also take antihistamines. When those are not enough, several off-label therapies are available, Friedman said. Omalizumab can be used to treat chronic hives.
As with any patient at risk for anaphylaxis, people with cold urticaria should be prescribed an epinephrine pen, the authors of the case report wrote.