RESULTS:
The original search retrieved 689 unique citations; six additional articles were found via references and three via Pubmed alerts, of which 52 were full-text screened. The final search retrieved 8 additional articles, which were full-text screened. Overall, 17 studies were included (Fig. 1 and 2, and Table 1). Of them, three were randomized, double-blinded, placebo-control (RDBPC) studies17-19, five quasi-experimental prospective cohorts20-24, five prospective cohorts25-29, two retrospective cohorts30,31, and two case reports32,33.
Participants with hazelnut allergy were included in 14 studies, walnut in 1 17,18,20,21,23-27,33, cashew in 917,18,20,21,23-27, pecan in 717,18,20,21,24-26, almond in 517,20,21,26,27, and pistachio in 517,18,23,27,32.
The population in question was adults in three studies19,28,32, children in 514,17,27,31,33, and both in 918,20-26,29.
A detailed description of all the included studies, and studies that might appear to meet the inclusion criteria, but which were excluded, can be found in the Supplementary text.
Efficacy and safety