Sesquiterpene lactone mix is not an adequate screen for Compositae allergy

70 patients suspected or known to have contact allergy to Compositae were patch tested with 0.1% sesquiterpene lactone mix (SL mix) and individual Compositae oleoresins. There were no apparent cases of active sensitization by, or irritancy from, the SL mix. 6 patients had allergic reactions to both SL mix and Compositae oleoresins, while 11 patients had allergic reactions to Compositae oleoresins with a negative reaction to the SL mix. In all but 2 of these, Compositae allergy was considered clinically relevant. As 0.1% SL mix picked up only 35% of cases of Compositae allergy, we do not consider it an adequate screen.