I recently read that a study has shown that it's possible that, in 2 out of 3 cases, peanut allergy that has been diagnosed by SPT/RAST has been misdiagnosed because one of the peanut proteins, Ara h 8, is similar to a protein responsible for birch pollen allergy. The ImmnuoCAP allergen component test, which can quantitatively determine the reactivity to each individual peanut protein (Ara h 1, 2, 3, 8, 9, etc) is a relatively new test available in the US through Phadia (www.pirllab.com). Those with high reactivity to Ara 2, especially, are likely to have true allergy, according to an article in J Allergy Clin Immunology (2010;125:191-7).
Has anyone else heard about this or gotten this particular test? Your allergist would probably have to mail a blood sample to Phadia's lab. Any comments?