Cross-reactivity of pink peppercorn in cashew and pistachio allergic individuals

Background The Pink peppercorn belongs to the same Anacardiaceae family as cashew and pistachio. However, the cross-reactivity of pink peppercorn with cashew and pistachio has yet to be studied. To date, there has been a single case report of anaphylaxis to pink peppercorn in a cashew and pistachio allergic individual. Objective We aim to demonstrate cross-sensitization to pink peppercorn in cashew and/or pistachio allergic children. Methods A small descriptive cohort study looking at cross-sensitization of pink peppercorn in cashew and/or pistachio allergic children was conducted. Children with a history of reaction to pistachio and/or cashew nut underwent skin prick tests to the pink peppercorn species Schinus terebinthifolius to determine cross-sensitization. Results Out of the 21 cashew and/or pistachio allergic subjects, 16 (76.2%) demonstrated cross-sensitization to pink peppercorn. None of the subjects had any knowledge of previous exposure or allergic reactions to pink peppercorn. Discussion This study demonstrates potential cross-reactivity between pink peppercorn and cashew and pistachio. While an oral food challenge to pink peppercorn would have been important in demonstrating clinical cross-reactivity, this was not performed due to ethical constraints. We hope to increase the awareness of pink peppercorn as a potential and hidden source of allergen and encourage further studies to demonstrate the clinical cross-reactivity and to better delineate the major allergen involved.