Nine patients with strong skin reactions to chrysanthemums of florists were studied. From four different common chrysanthemum varieties, alcohol and aqueous extracts were prepared. Extracts of stems appeared negative while the highest skin reactivity was found in alcohol extracts of leaves and flowers. Aqueous extracts were mainly negative. No significant differences in skin reactivity between the four varieties assayed occurred. Six out of seven persons allergic to chrysanthemums showed positive reactions to alantolactone (a sesquiterpene lactone) and two of four who were tested showed positive reactions to cumambrin A.
Bleumink E, Mitchell JC, Nater JP. Contact Dermatitis to Chrysanthemums. Arch Dermatol. 1973;108(2):220-222. doi:10.1001/archderm.1973.01620230020007