ABSTRACT
Hair pigmentation and graying are important topics for the understanding of the physiology of aging; the differentiation of stem cells; and the mechanisms underlying disease processes such as progeroid syndromes, vitiligo, and hypothyroidism. Although hair graying, or canities, is a common process occurring in people as they age, an unknown percentage of individuals experience premature graying from familial inheritance or pathologic conditions. We review the physiology of hair pigmentation and the mechanism underlying physiologic graying, and we explore the etiology of pathologic causes of premature graying, pathologies associated with premature graying, and the limited available treatment options for hair graying.
Subject(s)
Hair Color , Hair Diseases/epidemiology , Hair Diseases/prevention & control , Hypopigmentation/epidemiology , Hypopigmentation/prevention & control , Adult , Age Factors , Aging , Female , Humans , Male , Young AdultABSTRACT
Adolescent androgenic alopecia is pattern hair loss occurring in boys and girls younger than 18 years, whereas early-onset androgenic alopecia refers to pattern hair loss before 35 years of age. A number of studies published in the last decade have helped to elucidate the prevalence of adolescent androgenic alopecia, have clarified the genetic as well as physiologic mechanisms underlying hair loss, and have revealed the associated psychologic and systemic morbidities. This article provides an overview of the pathophysiology, diagnosis, and treatment of adolescent androgenic alopecia.
