[Allergic contact dermatitis due to Asteraceae (Compositae). Cross reaction with Liatris spicata]

Case reports of 2 florists suffering from contact dermatitis to Asteraceae, especially to Chrysanthema are described. In addition, in both patients allergic patch-test reactions to another Asteraceae species (Liatris spicata) could be demonstrated. This Asteraceae species is a native flower (Blazing Star) in the USA, but in Germany we find the flower in shops, and sometimes in parks and gardens. Genus Liatris contains about 30 species. Numerous sesquiterpene lactons are isolated from Liatris species which are probably cross reactive with sesquiterpene lactons from Asteraceae native to Europe.