Australian research identifies way to improve peanut allergy diagnosis

Posted by AFN Staff Writers on 21st March 2012

Researchers from Murdoch Children’s Research Institute and the University of Melbourne have identified a new way to accurately test for peanut allergy.

It is hoped the test will be more cost effective and convenient than standard approaches and minimise over-diagnosis of peanut allergy in the community. The research was published in the Journal of Allergy and Clinical Immunology this week.

Currently, an oral food challenge is the standard for diagnosing peanut allergy, and while an oral food challenge is definitive in diagnosing patients, it is time-consuming, costly and patients risk severe reactions such as anaphylaxis.

The new test researchers have identified uses part of the peanut protein called ‘Arah2’ and involves a two-step screening process. The researchers found they could perform a blood test, followed by the Arah2 test, which was more accurate and highly predictive than using one of the tests alone. They found the two-step testing process reduced the need for oral food challenges by four-fold.

Co-lead researcher, Thanh Dang, a University of Melbourne PhD student based at the Murdoch Childrens Research Institute, said reducing the number of oral food challenges helps prevent many peanut allergics undertaking the unnecessary risks involved with an oral food challenge.

Associate Professor Katie Allen said the new test could reduce the burden on clinicians and the health care system.

“Due to the rapid increase in rates of sensitisation to foods, allergy services are overwhelmed, and food challenge tests might be difficult to access. This method would help alleviate the current strain and demand on clinical allergy services, with the allergy patient waiting times in excess of 18 months in many centres in Australia,” she said.

Researchers say the test would also help minimise over-diagnosis, and would reduce the number of patients requiring referral to specialist services for confirmation of a food allergy, by using oral food challenges.

Patients would simply need to visit a GP rather than require a referral to a specialist allergy clinic.

Diagnosis of peanut allergy is relatively straightforward when there is an obvious history of clinical reaction to peanut ingestion. However, diagnosis can be more complicated in cases in which the clinical history is not clear or in children who have not yet been exposed to a food.

Researchers say the new ‘Arah2’ two-step process can be used in children with high risk of food allergy, such as those with eczema and other food allergies and for those who have not eaten peanuts but have a strong family history of food allergy.