Hair shaft disorders, involving dysplastic abnormalities in the shaft, may be either congenital or acquired. Two large categories have been defined according to the presence or not of hair fragility. A diagnosis can usually be made after taking a thorough medical history and performing a physical examination. Trichoscopy has become a useful, cost-effective tool in recent years, particularly for examining the hair of children, because it facilitates inspection without removal of hairs. Structural abnormalities in the hair shaft are sometimes clues to the diagnosis of more complex diseases in which early treatment can improve prognosis. This review describes key features that enable the diagnosis of the most common hair shaft disorders and discusses the various treatments currently available.
