Allergy
-
Oral allergy syndrome (OAS) is often associated with pollen-induced rhinitis, and there are preferential associations between causative substances. If OAS and rhinitis are both immunoglobulin (Ig)E-mediated and there are cross-reacting proteins, it is expected that similar reactions can be elicited in the nose and mouth. In order to test this hypothesis we performed a series of 'cross-challenges' with foods and pollens in both the nose and the mouth. ⋯ The cross-reactivity between foods and pollens, when evaluated at the shock organ, was not clinically evident. This data can be explained with a low concentration of cross-reagent epitopes in pollen extracts and food homogenized because of degradation. The different behaviour upon challenge suggests that different immunological mechanisms may act in the nose and mouth.