Component-resolved diagnostics: shedding light on the so-called 'squishy science' of food allergies?

body. Component-resolved diagnostics (CRD) has been introduced recently as a promising tool to assess specific IgE antibodies against multiple recombinant or purified natural allergen components. CRD has been widely utilized for research purposes with the application of protein as well as peptide microarray chip technology. One of the advantages of the chip technology is the ability to obtain a wealth of information from a minute amount of blood, which is particularly helpful in infants and young children. CRD provides significant insights into the process of sensitization by defining the primary sensitizers, cross-reactivity patterns, and potential markers of systemic reactions in plant food allergy. This issue’s article by Moverare et al. [3] evaluates 74 Swedish subjects with known peanut sensitization and a history of suspected peanut allergy. Within this cohort, 65% of subjects had specific IgE antibodies to Ara h 1, 2, or 3 whereas 35% had no detectable IgE antibodies to these recombinant peanut storage proteins. Among the group positive to Ara h 1–3, 60% of subjects had peanutspecific IgE levels 1 15 kU A /l (median 21 kU A /l) whereas all subjects in the group negative to Ara h 1–3 had peanutRecently, the editors of the New York Times invited knowledgeable outside contributors to discuss the systematic review of the available evidence on the prevalence, diagnosis, management, and prevention of food allergies published in the Journal of the American Medical Association in 2010 [1] . They entitled their blog ‘The Squishy Science of Food Allergies’ [2] , and it was a discussion triggered by the commissioned federal report which found that a uniform definition of what a food allergy is or how to test for one was lacking. There were few highquality studies. The New York Times title may somewhat belittle the complexities of the diagnosis of food allergies but also conveys the difficulties inherent in our less-thanperfect testing modalities available for food allergy. Modern society favors instant and definitive outcomes, primarily because technology has allowed for such. However, immediate conclusions cannot always be reasonably delivered in medicine and particularly in food allergy. Certainly, the diagnostic value of our current testing modalities via the blood and skin are limited by the relatively low positive predictive value (PPV) and are overly sensitive in detecting relevant specific IgE antiPublished online: June 29, 2011