Peanut allergy affects 3 per cent of children and is most commonly associated with severe and fatal allergic reactions.

According to a new study conducted by Murdoch Children’s Research Institute, Melbourne, a test can now predict which children will outgrow their peanut allergy by the age of four.

The study recruited 5,276 one year olds and skin prick tested them to common food allergens, including peanuts. The findings revealed 22 per cent of children outgrew their peanut allergy by the age of four.

The children found to be sensitive to peanuts participated in an oral food challenge to diagnose their peanut allergy, confirmed in 156 infants. At the age of four, the same children underwent another oral food test to assess whether they had outgrown their peanut allergy.

Researchers found children with higher levels of IgE were less likely to develop a tolerance to peanuts while those with lower levels of IgE were likely to outgrow their peanut allergy by age four.

Other factors, such as co-existing food allergies, tree nut, house dust mite sensitisation, eczema and asthma were considered, however none were predictive of persistent peanut allergy.

According to lead researcher, Professor Katie Allen, Director of Population Health and Group Leader of Gastro and Food Allergy, Murdoch Children’s Research Institute, said the ability to predict which children will have ongoing peanut allergies will help doctors manage their care.

“These thresholds are the first to be generated from a population-based study where all participants were tested from an oral food challenge, skin prick testing and blood tests at both diagnosis and follow-up.

“These predictive factors identified will be useful in reducing the need for unnecessary oral food challenges in children with high risk of persistent peanut allergy,” said Professor Allen.

The study published in the Journal of Allergy and Clinical Immunology is the first population based study to investigate the natural history of peanut allergy.