Monilethrix: An Ultrastructural Study

The study on monilethrix examined the ultrastructure of affected hair using electron microscopy. It found that the characteristic moniliform hairs had alternating nodes and internodes, with nodes appearing normal and internodes being thin with ridges and flutes. The internodes showed wrinkling of cuticular cells and a reduced number of cortical cells, although the size and keratin pattern of cortical cells were normal in both nodes and internodes. These findings suggested that the internodes were the pathological parts of the hair, likely due to periodic dysfunction in the hair matrix, particularly in the hair cortex.