Pili Annulati with Fragility: Electron Microscopic Findings of a Case

In the 2012 case study, a 14-year-old girl with fair skin and dark hair was diagnosed with Pili annulati (PA) with unusual hair fragility, a deviation from the typical PA which does not involve hair fragility. The patient had experienced easily breakable, shiny beaded hair since she was four years old. Light pull tests resulted in a few broken hairs, and transmitted light microscopy showed periodic dark bands on the hair shaft, which disappeared after treatment with 10% aqueous potassium hydroxide. Electron microscopy revealed multiple cavities within the hair shaft and severe cuticular damage indicative of weathering. These findings supported the presence of fragility in PA, suggesting that the fragile hair structure in PA may be due to pathological cavities within the hair shafts.