Having a pet dog reduces a child's risk of developing a food allergy before the age of four, new Australian research has identified.

Nearly two thirds of children with a food allergy will have outgrown it by the age of four, Australian research has found.

But the prevalence of food allergies among Australian children is still remarkably high compared to other countries.

The Murdoch Children's Research Institute (MCRI) has released the findings of a "robust" study conducted at the Australian Centre of Food and Allergy Research.

The HealthNuts study involving more than 5000 kids, recruited at the age one, showed food allergy reduced from 11 per cent at age one to 3.8 per cent, or 1 in 25, at age four.

Outgrowing egg allergy was the main driver of this change, dropping from 9.5 per cent to 1.2 per cent.

The prevalence of peanut allergy fell from 3.1 per cent to 1.9 per cent.

Lead author Dr Rachel Peters, from MCRI, says the study showed up to 50 per cent experienced symptoms of any allergic disease in the first four years of their life.

Asthma prevalence was 10.8 per cent, eczema was 16 per cent and hayfever 8.3 per cent.

Importantly, the study also identified risk factors for food allergy.

"We've found that children who have older siblings and children who have pet dogs early in life are less likely to develop food allergies," said Dr Peters.

Children born in Australia with Asian-born parents had higher rates of food allergies, she said.

It's hoped the identification of risk factors will lead to potential intervention to protect kids from a condition that can be life-threatening.

A severe allergic reaction to peanuts can cause anaphylaxis - a medical emergency that results in difficulty breathing and the swelling of the tongue and throat.

Participants of the HealthNuts study will be followed up at age six and 10.

The study is published in the Journal of Allergy and Clinical Immunology.