Food allergy to pumpkinseed--characterization of allergens

In recent years, pumpkinseed has become increasingly popular as a foodstuff. Here we report the occurrence of allergic reactions (itching and swelling of oral mucosa, and asthma) to this member of the Cucurbitaceae family. We investigated three patients suffering from symptoms after ingestion of roasted pumpkinseed. All the patients fished for sport and used pressed pumpkinseed flour as bait. Sera were tested by the immunoblot technique for IgE reactivity with proteins of pumpkinseed extract. The immunoblot revealed pumpkinseed allergens of 13, 14, 36, 48, 77, and 87 kDa. Inhibition experiments with recombinant birch profilin were performed: IgE binding to the 14-kDa allergen was completely blocked by preincubation of the sera with recombinant birch profilin. In conclusion, type I allergy to pumpkinseed is rare, and the patients' histories suggest inhalation of pumpkinseed flour during fishing to be the relevant route of sensitization, leading to food allergy to pumpkinseed.