Clinical Uses of Hydroxyacids

Hydroxyacids are low pH substances that exfoliate the stratum corneum and modulate the process of keratinization. The hydroxyacids include alpha-hydroxyacids (AHAs), beta-hydroxyacids (BHAs), polyhydroxy acids (PHAs), aldobionic acids (bionic acids), and aromatic hydroxyacids (AMAs). Effects of hydroxyacids include increased thickness of epidermis and papillary dermis; improved barrier properties; increased amounts of hyaluronic acid in the dermis and of other dermal glycosaminoglycans which correspond to increased skin thickness measured micrometrically; improved histologic features of dermal collagen; increase in total skin thickness which in turn diminishes clinical wizened appearances; and diminished dyspigmentation. PHAs and bionic acids can be distinguished from AHAs in that they are gentle, moisturizing and provide skin protective benefits including MMP inhibition, antioxidant/chelation effects and reduced non-enzymatic glycation. Hydroxyacids are effective skin peeling agents.