Abstract
Hair shaft disorders can be congenital or acquired, which can be caused by trauma. Congenital hair defects are usually present at birth or they become evident in the first months of life. Patients can present with localized or diffuse alopecia, and some hair shaft defects can also simulate hair loss and should be considered in patients with abnormal hair growth. Many of these conditions show peculiar dermatoscopic findings, which will be described in this chapter.