RESEARCH LETTERS Food-dependent exercise-induced anaphylaxis (FDEIA) by nectarine in a paediatric patient with weakly positive nectarine prick-by-prick and negative specific IgE

Food-dependent exercise-induced anaphylaxis (FDEIA) is characterised by the onset of anaphylaxis during (or soon after) exercise preceded by ingestion of a food allergen. In FDEIA, both food allergens and exercise are independently tolerated. This syndrome has been associated with wheat, seafood, peanut, egg, milk, vegetables and fruits. Rosaceae fruits may also be involved. There are two major clinical patterns of allergy involved with this fruit family. One is the oral allergy syndrome (OAS) caused by sensitisation to Bet v 1 -a homologous protein in patients with birch pollens allergyand/or caused by sensitisation to profilin. The other one is associated with sensitisation to lipid transfer proteins (LTP), and may cause both OAS and systemic reactions -as FDEIA -and is often observed in patients living in the Mediterranean area. We report a paediatric case of FDEIA induced by nectarine (a variety of peach), with undetectable serum specific IgE to peach LTP (Pru p 3). A 14-year-old boy, with a history of seasonal allergic rhinitis caused by both grass and cypress pollens, experienced an episode of FDEIA during an intense exercise after eating Rosaceae fruits. In August, during a break of an athletic race, he ate two nectarines with peel and after a few minutes he started running again and immediately experienced bilateral ocular oedema, nasal obstruction and ocular and nasal itching. Before this episode, the boy was regularly eating nectarines with peel, even if he never performed physical exercises after eating this fruit. Skin prick tests (SPT) with commercial peach extract and prick-by-prick (PP) with peach (pulp and peel) were performed two weeks later, and had uncertain outcome (mean wheal diameter 2 mm). Since then, the boy no longer eats Rosaceae fruits and kept doing sports (about four times a week) without any adverse reaction. We met the boy for the first time in October, when nectarine was not a seasonal fruit. So we were not able to perform PP with fresh fruit at that time, and we performed PP in the next summer.