Sunburn and Apoptosis

Abstract

For a sufficient dose of ultraviolet radiation, the human skin reacts by erythema which will develop a few hours after exposure and will culminate 20 hours later. Among the histological modifications observed on skin biopsies performed on the irradiated skin, Daniels F. Jr. et al., (1961) described, within the epidermis, cells with unusual and distinct morphological characteristics ”A shrunken, homogenized, densely stainel glassy cytoplasm and a hyperchromatic condensed pyknotic nucleus”. The light microscope appearance of the cell is that of a dyskeratotic, faulty and premature keratinization of isolated keratinocytes. Disulfide (S-S) groups normally present in the horny layers are present in these cells (Danno and Horio 1980) called ”sunburn cells” (SBCs). The association of SBCs formation with the cell cycle has already been suspected by Danno et al., (1981). The description was completed, at the ultrastructural level, with the recognition of the loss of desmosome attachments, of pericellular and perinuclear edema and of clear vacuolated cytoplasm.