Cashew Nut Allergy in Children

The content of the thesis contributes to the knowledge of the cashew nut and cashew nut allergy. Cashew nut allergy is an important healthcare problem, especially in children. The cashew nut (Anacardium occidentale) belongs to the Ancardiaceae family and the major allergen components of the cashew nut are Ana o 1, Ana o 2 and Ana o 3. We performed a prospective multicentre study: ‘Improvement of Diagnostic mEthod for ALlergy assessment ( IDEAL-study) with 179 cashew nut sensitised children (median age 9.0 years; range 2-17 years). The children underwent a double-blind, placebo-controlled challenge (DBPCFC) with cashew nut and specific IgE to cashew nut and to the components Ana o 1, 2 and 3 were determined. A skin prick test (SPT) with cashew nut extract was performed.
Of the children, 137 (76.5%) had a positive DBPCFC test and the children most frequently showed gastro-intestinal symptoms. A minimal amount of cashew nut caused allergic reactions.
To improve the diagnostic method, a multivariate model with scoring system to predict the outcome of the DBPCFC test with cashew nut was developed. Gender and Ana o components (with and without skin prick test (SPT)) showed the highest discriminative ability (concordance-index = 0.90 with SPT and 0.89 without SPT). In situations where there is limited availability of double blind testing for suspected cashew allergy, the use of the model and scoring system may be useful for identifying children who have ≥ 95% chance of having a positive challenge test result and in whom such testing is less likely to influence management. In our present series, this pertains to a substantial number of patients (34%).