At inclusion , the forearms/arms of each volunteer were randomized to receive for 1 week either an o/w formulation containing licochalcone A ( Glycyrrhiza Inflata root extract ) , decanediol , menthoxypropanediol and -6 - fatty acids ( emollient arm ) or 1 % hydrocortisone ( HC arm ) ; after 1 week , the application of the emollient and HC were discontinued and the volunteers applied a w/o emollient containing licochalcone A and -6 - fatty acids on both arms for further 3 weeks .