Development of pollinosis after ingestion of pollen.

We describe the case of a patient who developed distinct allergic reactions after the ingestion of commercially available "pollen food", while according to the history there had been no previous complaints to aero-pollen. By both in vivo as well as in vitro testing a simultaneous sensitivity to grass, tree and weed pollen, as well as to the main components of "pollen food" rock rose and viper buglows pollen could be proven. With the help of RAST-inhibition, cross-reactions between the different pollen allergens were traceable. In the pollen season after the allergic incident, the patient developed pollinosis symptoms for the first time, which intensified in the following season. On these grounds, we believe that (1) the repeated ingestion of "pollen food" resulted in a sensitization against its allergens and, due to the cross-reactions, against aero pollen allergens as well and that (2) an "allergic breakthrough" caused the manifestation of pollinosis symptoms.