Dermatoscopy of Hair Shaft Disorders

The 2013 document reviews dermatoscopy, also known as trichoscopy, as a noninvasive technique for diagnosing hair shaft disorders, highlighting its convenience and efficiency compared to traditional methods like light microscopy. It details the dermatoscopic features of various congenital and acquired hair shaft disorders, such as monilethrix, trichorrhexis invaginata, pili trianguli and canaliculi, trichorrhexis nodosa, and bubble hair. The document also describes how dermatoscopy can distinguish between disorders like pili annulati, woolly hair, pili bifurcati, and multigemini, and can be used to differentiate these from alopecia areata. It notes the utility of dermatoscopy in identifying peripilar casts and scalp infestations. The conclusion states that while dermatoscopy is a valuable diagnostic tool, providing magnifications from ×10 to ×160, it is sometimes used to select hairs for further examination under light microscopy, as in the case of trichothiodystrophy.