Anaphylaxis rates have more than doubled for Australian children aged between five and 14, according to a new study.

The number of Australians hospitalised with severe life-threatening allergic reactions has increased by 50 per cent between 2005 and 2012.

Hospital admissions increased in all age groups, while the highest rates are still for patients under five with the cause mainly being food allergy, according to the Murdoch Childrens Research Institute study.

The research, published in the Journal of Allergy and Clinical Immunology, examined admission rates for anaphylaxis between 1998 and 2012 to see if childhood food allergy and anaphylaxis had increased further since 2005.

"We saw an overall 50 per cent increase in anaphylaxis admissions, and between a 30 and 50 per cent increase in most age groups", said lead researcher Dr Raymond Mullins.

Although the highest rates were for children under four, there was a 110 per cent increase in rates for those aged between five and 14.

"What was most interesting was that while the rate of increase is steady in most groups, we saw an acceleration in the rate of increase in this age group," he said.

"Now one of every 500 hospital admissions in this age group is to treat anaphylaxis."

He noted the `food allergy generation' was born over a decade ago.

"We are now seeing food allergy and anaphylaxis turn into a chronic condition that for many individuals will not disappear, with a possible eventual flow-on effect to rates of fatal food allergic reactions which are most common in these age groups."

The challenges facing the healthcare system included was how to prevent the development of new food allergies in very young children and how best to care for the increasing numbers of new cases in younger children, he said.