Keys to the diagnosis of hair shaft disorders: Part I. / Claves diagnósticas en displasias pilosas I.

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.

Keys to the Diagnosis of Hair Shaft Disorders: Part II. / Claves diagnósticas en displasias pilosas II.

Hair shaft disorders, involving dysplastic abnormalities in the shaft, may be caused by genetic mutations or acquired through environmental exposures. The second part of this review presents these disorders classified according to the degree of hair fragility. It is important to take a thorough medical history and examine the hair to detect changes in texture, density, quality, and whether fragility is observed or not. Trichoscopy is a useful, noninvasive tool that can suggest a diagnosis in most cases. Specific treatments for hair shaft disorders are not available at present. We recommend general care practices to prevent hair damage; examples are avoiding excessive brushing, chemical products, hairstyles that introduce tension, and exposure to excessive heat. Some hair shaft disorders improve with puberty. Others may respond to treatments such as topical applications of minoxidil.