Diluted Compositae mix versus sesquiterpene lactone mix as a screening agent for Compositae dermatitis: a multicentre study

The objective of this study was to compare diluted Compositae mix with sesquiterpene lactone mix as a marker for Compositae dermatitis. Patients undergoing diagnostic patch testing in 8 British Isles patch test centres were also patch tested to sesquiterpene lactone mix (0.1% pet.) and Compositae mix (3% pet. or 0.6% pet.). Of a total of 5574 patients tested, 71 (1.3%) reacted to Compositae mix, 57 (1.0%) reacted to sesquiterpene lactone mix, and 45 to both. Diluted Compositae mix remained a more sensitive screening marker for Compositae allergy. We recommend that patients are patch tested to both agents.