Pollen food syndrome: update on the allergens.

Pollen food syndrome results from cross-reactivity between pollen-specific IgE and homologous proteins found in fruits and vegetables. These proteins can be grouped into several categories based on structure and include profilins, pathogenesis-related proteins, and cross-reactive carbohydrate determinants. Although cooking the reactive fruits and vegetables has been shown to destroy IgE-binding epitopes, evidence suggests that the remaining linear epitopes can bind cross-reactive T cells and enhance T-cell activation in vitro. Several methods of diagnosing food allergies exist, including skin prick tests and double-blind food challenges; however, diagnosing pollen food syndrome depends almost exclusively on clinical history. Immunotherapy has been studied as a treatment for pollen food syndrome, with highly variable results.