But the reason for the increase remains a mystery, an expert says.

The number of admissions to Canberra hospitals for people with anaphylaxis rose from 74 to 100 in the two financial years to 2014-15, while the number of children with potentially life-threatening allergic reactions jumped from 12 to 22.

Adverse reactions to food such as cow's milk, egg white and peanuts were the most common causes.

The director of immunology at the Canberra Hospital, Professor Matthew Cook, said while the data revealed a rise only in recent years and the numbers were not large, he believed it reflected a broader trend occurring across Australia and other developed countries.

A joint study between the University of Canberra and the Murdoch Children's Research Institute in Australia found that rates of hospitalisation from anaphylaxis in Australia increased by 50 per cent between 2005 and 2012.

Professor Cook said this could have something to do with the "hygiene hypothesis," which is essentially the idea that societies are becoming too clean.

It's based on research that claims children who are kept in really clean environments have a higher rate of hay fever, asthma and a variety of allergies.

"There have been some studies that compare children growing up in rural settings with those growing up urban settings," he said.

"But as the name suggests, it is a hypothesis. And while it provides some circumstantial evidence that it might be connected to the hygiene in the environment, there isn't much biology to support the mechanism and what's happening in the immune systems for people having these reactions."

Though anaphylaxis is usually triggered by food, it can be caused by environmental factors, which is called contact dermatitis.

Professor Cook said some people developed serious allergic reactions to the cold, water, exercising or to having pressure on their skin.

Ink used for newspapers is the enemy to Canberran Jessica Charley's skin.

"I touched it by accident the other day with just one finger while I was getting into my house, and immediately it started getting really red and itchy," she said.

Ironically, former bartender Alexandra Furniss has the same reaction when she touches alcohol.

"I also tried consuming alcohol when I was 18 and vomited not long after, so I've stayed away from drinking alcohol ever since," she said.

Professor Cook stressed these conditions rarely developed into anaphylaxis, and the range of common causes was surprisingly narrow.

"The way the immune system is activated during contact dermatitis is different to when a food or drug triggers anaphylaxis, but the manifestations are similar and in some cases it can be very serious," he said.

"Usually anaphylaxis is a bit more boring than that and is often due to stings, drugs or food."

"But we still have much to learn about the actual mechanisms of allergic disease and the more we know the easier it will be to resolve why it seems to be increasing in prevalence."