[Exogeneous hair damage caused by bleaching and cold waving. A case report with scanning electron microscope studies]

A case of exogeneous hair damage caused by bleaching and cold waving is reported. The clinical picture showed brittle, lustreless, fallow hair. The light microscope showed irregular spreading of the cuticular cells. The scanning electron microscope revealed loss of the regular cuticular pattern, breakage of the edges of the cuticular cells, and wave-like separations of the cuticular cells from the cortex. The hair shafts showed multiple longitudinal indentations like seen on a tree trunk.