Dowling Oration delivered at the Royal College of Physicians, London, Friday 5 June 1998. Retinoids: renaissance and reformation

There is confusion as to the cutaneous signs of ageing. For the most part the features of photoageing, namely actinic lentigines and wrinkling, are misinterpreted as features of ageing. Wrinkling is associated with a loss of collagens from the papillary dermis resulting from imperfect remodelling of the dermal extracellular matrix following sun exposure. Retinoids are either derivatives of vitamin A or synthetic ligands of nuclear retinoid receptors. Retinoid receptors, notably retinoic acid receptor gamma and retinoid X receptor alpha are present in human skin. Topically applied all-trans retinoic acid can repair and probably prevent photoageing of the skin by modulation of collagen synthesis in the dermis. There is emerging evidence that intrinsic ageing of the skin is also amenable to reversal by topical retinoids.