title: A practical, algorithmic approach to diagnosing hair shaft disorders.
abstract: The hair shaft is a unique structure composed of an inner cortex and a protective outer cuticle. Any defects in this normal structure due to genetics or the environment can lead to variations in physical properties. Thus one should suspect a hair shaft disorder if a patient presents with an abnormality or change in hair texture, appearance, manageability or ability to grow hair long. A key feature of the clinical evaluation is to determine whether there is hair breakage (increased fragility) by looking for broken hairs and performing a tug test. Once this determination is made, an algorithmic approach can be used to narrow the differential diagnosis: hair shaft disorders with and without fragility. A hair mount along with other directed questions and examination will almost always allow the clinician to make an in-office diagnosis. Common case scenarios, photographs, and practical tips are provided to illustrate the use of this algorithmic approach in the diagnosis of hair shaft disorders. We have also included a summary of the molecular defects where known, which can be helpful in providing a correlation with clinical findings, in counseling patients, and potentially offering treatment options.
authors.affiliation: Department of Dermatology, Kaiser Permanente Vallejo Medical Center, Vallejo, CA 94589, USA. paradi.mirmirani@kp.org
authors.forename: Paradi
authors.initials: P
authors.lastname: Mirmirani
authors.forename: Kathie P
authors.initials: KP
authors.lastname: Huang
authors.forename: Vera H
authors.initials: VH
authors.lastname: Price
mesh_terms: D000465:Algorithms; D002648:Child; D005260:Female; D006197:Hair / Q000002:abnormalities* / Q000737:chemistry / Q000473:pathology*; D006201:Hair Diseases / Q000175:diagnosis* / Q000473:pathology; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D008297:Male; D028361:Mitochondrial Diseases / Q000151:congenital