I'm freezing and… a little itchy! A rare condition called cold urticaria

As we venture deeper into the winter months, you may have been noticing itchy red welts on your skin when exposed to the cold – that is, if you’re part of the 0.05% of the population affected by the rare allergic skin condition known as cold urticaria.

What is Cold Urticaria?

Also known as cold contact urticaria or acquired cold urticaria, this condition typically affects young adult women, though even children and not-so-young adults can also be affected. It’s a type of chronic inducible urticaria, characterized by recurrent hives for at least 3 months, attributed to a known trigger (in cold urticaria, the trigger is cold).

Those with cold urticaria experience itchy welts (hives), redness, and swelling when their skin is exposed to cold. This can be from stepping out into the cold winter air, plunging into an ice bath, or even walking past the refrigerator section of the grocery store. In severe cases, cold exposure can lead to anaphylaxis.

The symptoms of cold urticaria usually pop up within 5 minutes of cold exposure and can last for a couple of hours. The symptoms can be variable between individuals, but may include:

• Itchy welts (hives) on the part of the skin exposed to the cold
• Hives and swelling as a generalized rash all over your body
• Itching, swelling, and redness that worsen when your skin warms back up
• Symptoms of anaphylaxis, including difficulty breathing, abdominal pain, rapid and irregular heartbeat, and fainting

A severe and life-threatening anaphylactic reaction is more likely if your whole body is exposed to the cold, such as swimming in cold water or being in a cold room. Having surgery under general anesthesia has also been known to trigger anaphylaxis-level cold urticaria.

What Causes Cold Urticaria?

Cold urticaria can be divided into two categories: idiopathic (primary) cases and secondary cases. There’s no real explanation for primary cold urticaria. Doctors suspect there may be a genetic predisposition, and up to 50% of people with cold urticaria have a known tendency for allergic conditions.

Conversely, secondary cold urticaria occurs due to another medical condition, such as certain cancers or viral infections.

In this condition, cold exposure triggers mast cells in your immune system to release histamine. If histamine sounds familiar to you, it’s because you have most likely heard of antihistamine medications, which are formulated to do exactly as it sounds – counter the effect of histamine. Histamine is a chemical in the body with a number of important roles, including regulating sleep and rallying the troops of your immune system to fight invading germs. But in cold urticaria and other allergic conditions, it can also have the unfortunate effect of causing itching, swelling, and redness in response to harmless stimuli. Why your body views cold exposure as an invitation for a histamine confetti party is anyone’s guess.

Managing Cold Urticaria

Diagnosing cold urticaria takes a very sophisticated and delicate piece of equipment known in medical circles as… an ice cube. Holding this highly precise instrument against your skin for a few minutes and then removing it will induce a skin reaction within 10 minutes, which your allergist can then identify as cold urticaria. And just to be thorough, you will likely also need a couple of other tests to check for underlying disorders that may be contributing to secondary cold urticaria.

There’s no cure for cold urticaria, though it often disappears on its own within weeks or months. Around half of cases have self-resolved within 5 years. In the meantime, you can manage cold urticaria by:

• Avoiding swimming in cold water: temperatures above 77°F are typically okay for most people. You could consider dipping a hand or foot into the water first and waiting to see if your skin reacts before taking the plunge (literally)
• Avoiding cold food and drink: swallowing cold things can be a trigger for a reaction in the throat for some people, leading to swelling of the airways and possible anaphylaxis
• Ensuring other healthcare professionals know about your condition: intravenous medications or fluids may need to be warmed up, and your surgery team will need to take extra precautions if you’re having a procedure under general anesthesia
• Taking high-dose antihistamine medications if you do experience a reaction
• Keeping epinephrine medication on you if you’re at risk of anaphylaxis from the cold

If you have cold urticaria, you already know that it can be difficult to avoid the cold. Even in the heat of summer, someone with cold urticaria will need to be cautious of Slushies, air conditioning, chilled drinks, and unheated outdoor pools. Coming under the care of an allergist can help you confirm your diagnosis and provide handy tips on managing and avoiding your triggers.