Meet the woman who loves snow but is literally allergic to the cold.

She was at a friend’s house playing under the sprinkler, in the backyard.

“We were running around and she all of the sudden had this look on her face and was like ‘Oh my gosh, what’s all over your back?’,” Ms Keall said.

“And it turns out my back was red raw, with hives all over it.”

Her alarming discovery was promptly followed by a visit to the family GP.

“The doctor gave it some big long name, and turns out it was cold hives. That was a good 20 years ago now,” she said.

“I’ve just been living with this … not thinking that anyone else had it or that there was anything I could do with it, because it was so strange.”

“Cold breeze can trigger a reaction”

Cold hives, also known as cold urticaria, is essentially an allergy induced by the cold. All it takes for people with the condition to have a reaction is an unexpected cold breeze, a trip down the freezer aisle at the supermarket, or even a sip from an icy drink.

Ms Keall, who lives near Melbourne, says in the last 20 years she has not gone one day without a reaction.

“Your fingers swell up sometimes on your hands … I get them on the palms of my hands and the bottom of my feet as well. It’s really uncomfortable. And if it’s summer and I go swimming in a swimming pool or in the beach, I get a full body reaction where my nerves become painful.”

Cold urticaria is a condition many people have never heard of.

Our collective understanding of allergic disease is based on our experience of common conditions such as hayfever or eczema, and serious allergies like those triggered by foods, like eggs and peanuts, or medications and insect bites.

According to the Australian Society for Clinical Immunology, allergies will affect about one in three Australians in their lifetime, and about one in 20 will develop a food allergy.

So how common is cold urticaria in comparison? According to Associate Professor Richard Loh, a clinical immunologist from Perth, there are no solid Australian figures.

“In a study done in Europe, one in 20,000 people have cold urticaria. It’s usually young adults but I’ve seen children as young as seven years with it, and older adults can also develop this condition,” he said.

A prevalence rate of one in 20,000 makes cold urticaria sound like a pretty rare disease.

But to put that in perspective, going by this study, in a city like Sydney, which has about 5 million people, you would expect to find about 250 people with cold urticaria.

A ‘medical mystery’

What triggers a reaction and its severity differs between people, but the result can be anything from a mild skin irritation, to anaphylaxis — a severe systemic reaction, that can be life threatening, which includes symptoms such as difficulty breathing and speaking, swelling of tongue and throat, abdominal pain, vomiting or loss of consciousness.

Associate Professor Loh says for doctors and specialists with knowledge of the condition, diagnosing cold urticaria is usually fairly simple.

“It’s important to get a good history of when did it occur, what were you doing, and from that you often get an idea that this is cold-induced urticaria,” he said.

“After that there are tests that can be done — something as simple as putting an ice cube onto a forearm and timing it to see whether hives develop at the area of contact.

“But I need to caution … if you have symptoms of systemic or anaphylaxis reactions, don’t do that yourself, because in some patients just putting an ice cube on the forearm not only causes urticaria, but can actually cause them to cough, wheeze or collapse.”

But the big question is — how does temperature trigger an allergic reaction?

“In our body we have cells called mast cells. So these are allergy cells that contain a lot of chemicals like histamine, leukotriene … things that are released during an allergic reaction to a food or an insect sting,” Associate Professor Loh said.

“But unlike with food or insects, where we can do specific skin tests or blood tests to try and identify what sets these mast cells off, in cold induced urticaria, usually the skin and blood tests are all negative to the allergens.”

In an allergic reaction triggered by a food or an insect bite, there’s usually an allergen involved — for example peanuts. Allergic people also usually have antibodies in their blood which get directed towards that allergen, triggering symptoms.

But for people who have cold-induced urticaria there is no measurable allergen or antibodies in the blood when a reaction takes place.

“We haven’t found it. Whether it’s the same mechanism as peanut or bee venom, we don’t know,” Associate Professor Loh said.

Genetics, treatments … and cold baths.

Doctors do know however, that for a small portion of sufferers the condition is inherited.

“There’s certain genes that are acquired with this small number of people, that runs through families. It’s very unusual,” he said.

In most cases though, the condition is not genetic. Occasionally it is triggered by an infection, such as glandular fever or a bacterial stomach ulcer. In these patients, sometimes treating the source of the infection also eliminates the urticaria. But for others, the cause remains unclear.

Treatment options are limited. Sometimes the condition resolves itself over time. For most the best option is to manage the problem — so that means avoiding the cold, and a big daily dose of antihistamines.

There is also a range of less common treatments, including antimalarial medications and drugs that suppress the immune system.

Lou Burnard, a 26-year-old legal secretary from Adelaide, found one of these less common treatments offered a reprieve from the condition.

She describes her experience with cold urticaria as “two years of hell”, without a proper diagnosis from her general practitioner.

“I did feel like I was dismissed,” she said.

“I got to the point where I couldn’t go shopping at the supermarket because I couldn’t go down cold aisles … I couldn’t eat anything cold because it would make my throat start to swell.”

After insisting on a referral to an in immunologist, Ms Burnard was prescribed a drug called Plaquenil — an antimalarial believed to interfere with communication between cells within the immune system. It took it more than six months for the drug to take effect, but it has helped her go into remission.

“She (the immunologist) said I’ll probably have to take it for about four years, so I’m still on it. But I haven’t broken out in hives. And I’ve got my life back,” Ms Burnard said.

There are a range of other “immune-modulating drugs” that have been used to treat cold urticaria. But Associate Professor Loh says there are drawbacks to these less common treatments.

“Some of the other drugs … do have side effects,” he said. “But they are very different from something that is usually very safe like an antihistamine.”

Another treatment option is desensitisation.

“There are research studies … where they introduce the patient to increasing amounts of cold. Sometimes it may be once a day spending a minute in a cool bath of water and every day slowly increasing how cold the bath water is,” Professor Loh said.

“But again this must be done with somebody with experience in this condition, because for some patients you can induce a severe, potentially life-threatening systemic reaction. I don’t have patients using this. It’s very hard to convince a child, a young adult to have cold baths in winter.”

‘I just love the snow’.

Ms Keall said she hopes a visit to specialist in the near future will provide some more treatment options. But in the meantime, avoiding the cold, or rugging up, is her best option.

She says life with cold urticaria can be tricky — and frustrating, particularly when people don’t take the problem seriously.

At times her urticaria limits where she can go, and what she can do.

“You weigh up your options in terms of certain things, whether the reaction is kind of worth it … in terms of sport and the gym and swimming and things like that,” she said.

But it’s amazing where good pair of mittens, a beanie, and a lot of determination will get you.

“I went skiing actually for the first time about a year ago at Blue Mountain in Canada and I just loved it — it was just beautiful,” Ms Keall said.

“Whenever I tell people ‘oh my gosh, I love the snow’ they kind of look at me funny. It causes me grief. But it’s just beautiful … there’s something peaceful about the snow.”