[Laurel allergy. Cause, effect and sequelae of the external application of a so-called nature remedy].

Self-medication of rheumatic complaints in the upper arm, by one woman, and of a lipoma on the thigh, by another, with pure laurel oil caused within two weeks severe contact dermatitis and swellings far from the point of application. Sesquiterpene lactone, contained within laurel oil, proved to be the cause of the induced contact allergy. Since the acquired specific hypersensitivity of the eczema type is directed primarily against the alpha-methylene group of the lactone, cross-reactions were observed against a large number of other plans which are botanically unrelated but contain substances of a similar class. Those allergic to laurel oil should therefore avoid many cosmetics, articles of hygiene, foods, drinks and medicinal preparations which contain herbs, as well as gardening, certain cut flowers and perfumes, especially those of the family Compositae. The present trend "back to nature" makes further sensitizations against laurel oil likely. This would seem to justify the inclusion of these substances among the group of potentially harmful environmental and occupational products.