title: Histologic features of alopecias-part I: nonscarring alopecias.
abstract: The diagnosis of disorders of the hair and scalp can generally be made on clinical grounds, but clinical signs are not always diagnostic and in some cases more invasive techniques, such as a biopsy, may be necessary. This 2-part article is a detailed review of the histologic features of the main types of alopecia based on the traditional classification of these disorders into 2 major groups: scarring and nonscarring alopecias. Scarring alopecias are disorders in which the hair follicle is replaced by fibrous scar tissue, a process that leads to permanent hair loss. In nonscarring alopecias, the follicles are preserved and hair growth can resume when the cause of the problem is eliminated. In the first part of this review, we describe the histologic features of the main forms of nonscarring alopecia. Since a close clinical-pathological correlation is essential for making a correct histologic diagnosis of alopecia, we also include a brief description of the clinical features of the principal forms of this disorder.
authors.affiliation: Servicio de Dermatología, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, España.
authors.forename: C
authors.initials: C
authors.lastname: Bernárdez
authors.affiliation: Servicio de Dermatología, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, España. Electronic address: lrequena@fjd.es.
authors.forename: A M
authors.initials: AM
authors.lastname: Molina-Ruiz
authors.affiliation: Servicio de Dermatología, Fundación Jiménez Díaz, Universidad Autónoma de Madrid, Madrid, España.
authors.forename: L
authors.initials: L
authors.lastname: Requena
mesh_terms: D000505:Alopecia / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D000506:Alopecia Areata / Q000000981:diagnostic imaging / Q000473:pathology; D001505:Beauty Culture; D001706:Biopsy; D006197:Hair / Q000254:growth & development; D018859:Hair Follicle / Q000473:pathology; D006801:Humans; D008853:Microscopy; D013314:Stress, Mechanical; D013587:Syphilis / Q000150:complications; D014256:Trichotillomania / Q000150:complications
keywords: Alopecia; Alopecia androgenética; Alopecia areata; Alopecia por tracción; Alopecia sifilítica; Alopecias no cicatriciales; Androgenetic alopecia; Dermatopathology; Dermatopatología; Efluvio telógeno; Nonscarring alopecia; Review; Revisión; Syphilitic alopecia; Telogen effluvium; Traction alopecia; Trichotillomania; Tricotilomanía