Objectives Several studies have described peach tree (PT) as an occupational allergen. The aim of this work was to assess the effect of Prunus persica 9 (Pru p 9), a recently identified allergen from PT pollen, in exposed workers.

Methods The study included people who reported respiratory symptoms after handling PT in orchards during the flowering period (Blanca village, Murcia region, south-east Spain). After completing a detailed questionnaire, participants underwent skin prick test (SPT) and nasal provocation test (NPT). The IgE response was analysed by SDS-PAGE and immunoblotting assays.

Results A total of 21 cases were included (mean age 45 years; 57% women). Most were polysensitised to common pollens, although one person was sensitised only to PT pollen. All cases had a positive SPT to this pollen, and 43% also to Pru p 9. All participants reported having rhinitis, and six participants reported having also asthma. Immunoblotting showed a heterogeneous IgE pattern for several proteins, with Pru p 9 recognised in nine cases. Most participants sensitised to PT pollen and Pru p 9 had positive NPTs, while those who were not sensitised to Pru p 9 tested negative.

Conclusions We demonstrate for the first time that Pru p 9, an allergen from PT pollen, can induce respiratory symptoms following occupational exposure. This must be considered a relevant allergen when people working with PT cultivars develop respiratory symptoms.