Allergic contact dermatitis due to sesquiterpene lactones.

Abstract

Several compounds containing the .alpha.-methylene-.gamma.-butyrolactone moiety were tested on human volunteers and on guinea pigs; the animals were experimentally sensitized by alantolactone, isoalantolactone and laurel oil. Of the 2 new lactones, spirolactone was more reactive. This was confirmed by animal and human testing. The synthetic lactones were less reactive than natural ones. .alpha.-Methylene-.gamma.-butyrolactone did not elicit cross-reactions in guinea pigs sensitive to alantolactone or to isoalantolactone, or in patients sensitive to sesquiterpene lactones. The .alpha.-methylene-.gamma.-butyrolactone group was necessary for cross-reaction, but to be active, it must first be substituted. Isolalantolactone a sensitizer and cross-reacts with alantolactone. The cross-reaction between laurel and Frullania, found in man, also occurs in guinea pigs. It is more evident when sesquiterpene lactone is the sensitizer and laurel is used to elicit reaction.