Increased Skin Irritation by Hydroquinone and Rsetinoic Acid Used in Combination

摘要

BackgroundHydroquinone (HQ) is frequently combined with retinoic acid (RA) to enhance lightening efficacy, which may also affect skin irritancy. Although skin irritation leads to postinflammatory hyperpigmentation, little research has been performed to compare skin irritancy between each component and the combination.