New test reduces peanut allergy diagnosis rates

Swedish immuno-diagnostics manufacturer Phadia has developed a new test that helps to differentiate between reactions to specific protein components of allergens. These new tests were used in a study by the Karolinska Institutet, Stockholm, which has shown that two out of three patients considered to be allergic to peanut are in fact allergic to birch pollen instead and had no or mild reactions to eating peanuts.

Several different proteins in peanut may be responsible for an allergic reaction in a sensitised individual, with the peanut protein known as Ara h 8 being structurally very similar to one of the proteins responsible for birch pollen allergy. Due to a cross-reaction to these proteins, many people sensitised to birch pollen will experience mild reactions after consuming peanut. Routine skin and blood tests are not able to differentiate between reactions to these two proteins, and therefore in the past patients have been diagnosed as having allergies to both peanut and birch pollen.

The new type of ImmunoCAP® Allergen Component tests will help to correctly diagnose children with birch pollen allergy rather than peanut allergy. Given the potential for severe reactions to peanut, a diagnosed peanut allergy can cause a great deal of stress and anxiety for those with the allergy, and their carers. The more specific tests may therefore improve the quality of life for many who have previously received a peanut allergy diagnosis.

As a result of these findings one of the researchers involved with the study, Dr Magnus Wickman from the Karolinska Institutet, advises parents of children diagnosed with peanut allergy to contact their physician and ask for additional laboratory testing using allergen component testing to confirm the result.

Additional information about the study and the new diagnostic tests can be accessed here

Study reference: Asarnoj et al. 2010 Allergy Vol 65(2). Pp 213 – 219.