Treatment of dermatitis from parthenin.

Composites and some other plants containing sesquiterpene lactones, frequently cause allergic contact dermatitis in man. No treatment is available to control this disease successfully. We have used an amino acid, cysteine, to treat allergic contact dermatitis in guinea pigs sensitized to parthenin, a major sesquiterpene lactone of an allergenic weed, Parthenium hysterophorus L. Cysteine treatment of the allergic reaction induced by parthenin resulted in (a) reduced time of recovery and (b) reduced intensity of the skin reaction.