BACKGROUND: Peanut and tree @entity9428 @entity566 are common, increasing in prevalence and the commonest food cause of @entity2021 . In the USA, 7.8% are sensitized (have @entity9428 -specific IgE), but not all those sensitized are @entity56 . Lack of data makes interpretation of tests for @entity9428 -specific IgE difficult. OBJECTIVES: This is the first study to investigate the clinical significance of test results for peanut and tree @entity9428 @entity566 in @entity56 or tolerant @entity1 . Findings are related to the severity of the @entity566 . METHOD: An observational study of 1000 @entity1 and adults @entity56 to at least one @entity9428 . History of reactions (severity graded) or tolerance to up to five nuts was obtained and skin prick test (SPT)/serum-specific IgE ( @entity9527 ) performed. RESULTS: There was no correlation between SPT size and graded severity of worst reaction for all nuts combined or for peanut, hazelnut, almond and walnut. For @entity9527 , there was no correlation for all nuts. Where @entity1 tolerated a @entity9428 , 43% had positive SPT of 3-7 mm and 3% > or = 8 mm. For @entity9527 , 35% were positive (0.35-14.99 kU/L) and 5% > or = 15 kU/L. In SPT range 3-7 mm, 54% were @entity56 and 46% were tolerant. There was poor concordance between SPT and @entity9527 (66%). Of @entity1 with a clear @entity9428 - @entity56 history, only 0.5% had negative SPT, but 22% negative @entity9527 . CONCLUSIONS: Magnitude of SPT or @entity9527 does not predict clinical severity, with no difference between minor @entity110 and @entity2021 . SPT is more reliable than @entity9527 in confirming @entity566 . Forty-six per cent of those tolerant to a @entity9428 have positive tests > or = 3 mm (sensitized but not @entity56 ). One cannot predict clinical reactivity from results in a wide 'grey area' of SPT 3-7 mm; 22% of negative CAPs are falsely reassuring and 40% of positive CAPs are misleading. This emphasizes the importance of the history. Understanding this is essential for accurate diagnosis. @entity1 with SPT > or = 8 mm and @entity9527 > or = 15 kU/L were rarely tolerant so these levels are almost always (in > or = 95%) diagnostic.

Interpretation of tests for @entity9428 XXXX in one thousand @entity1 , in relation to @entity566 or tolerance.

@entity1 :: ('9606', 'Species') :: ['children', 'Patients', 'patients'] @entity9428 :: ('256646', 'Gene') :: ['nut'] @entity566 :: ('MESH:D006967', 'Disease') :: ['allergy'] @entity56 :: ('MESH:D004342', 'Disease') :: ['allergic'] @entity9527 :: ('OMIM:115650', 'Disease') :: ['CAP'] @entity110 :: ('MESH:D014581', 'Disease') :: ['urticaria'] @entity2021 :: ('MESH:D000707', 'Disease') :: ['anaphylaxis']
@entity566 :: (MESH:D006967,Disease) :: ['allergy']
