Alantolactone sensitivity in chrysanthemum contact dermatitis

A case of occupational chrysanthemum contact dermatitis is reported. Patch tests showed the patient to be sensitized to Chrysanthemum morifolium (Chr M) leaves, flowers, and stems (alcoholic extracts) and to alantolactone. An attempt at desensitization appears to have been successful. Gas chromatography indicated the presence of alantolactone in all the various parts of Chr M, mostly in the flowers. The "maximization test" succeeded in sensitizing guinea pigs to alantolactone.