Allergic reactions to honey and royal jelly and their relationship with sensitization to compositae.

Honey and royal jelly are complex etherogeneous mixtures of flowers' nectar, sugars, proteins and bee's glandular secretions. The existence of a type I hypersensitivity to honey is still matter of debate, while an aetiological role of Compositae pollens in the clinical manifestations following honey ingestion has been envisaged. We describe two cases of severe systemic reactions (anaphylaxis and generalized urticaria/angioedema) due to honey and royal jelly ingestion in patients sensitized to compositae (mugwort). Both patients had a skin and RAST positivity to mugwort and a positive prick-by-prick to the offending foods. Moreover, in one of the two patients the RAST-inhibition assay showed the strong cross-reactivity between the proteins of honey and mugwort and the SDS-PAGE analysis showed that the major proteic bands from honey and mugwort extracts are largely superimposable. Both the clinical data and the laboratory analysis support the hypothesis of a strict link between sensitization to compositae and adverse reactions to honey and jelly.