title: Poliosis circumscripta: overview and underlying causes.
abstract: Although traditionally known as "white forelock," poliosis circumscripta, defined as a localized patch of white hair in a group of hair follicles, can involve any hairy area on the body including the scalp, eyebrows, and eyelashes. Microscopically, poliosis demonstrates either decreased or absent melanin and/or melanocytes in the hair bulbs of the affected hair follicles. Classically, poliosis is known to occur in the setting of several genetic syndromes including piebaldism, Waardenburg, and tuberous sclerosis. In addition, poliosis has been described in association with various acquired conditions. These include inflammatory conditions, benign and malignant neoplastic entities that are mainly melanocytic, medications, and others. In this review, we aim to describe the different conditions where poliosis may be encountered, with the aim of helping the clinician to better evaluate any patient presenting with poliosis.
authors.affiliation: Department of Dermatology, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Rima
authors.initials: R
authors.lastname: Sleiman
authors.forename: Mazen
authors.initials: M
authors.lastname: Kurban
authors.forename: Farah
authors.initials: F
authors.lastname: Succaria
authors.forename: Ossama
authors.initials: O
authors.lastname: Abbas
mesh_terms: D000328:Adult; D000465:Algorithms; D000506:Alopecia Areata / Q000453:epidemiology / Q000473:pathology; D001707:Biopsy, Needle; D015984:Causality; D015897:Comorbidity; D005260:Female; D006201:Hair Diseases / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology*; D018859:Hair Follicle / Q000473:pathology*; D006801:Humans; D017496:Hypopigmentation / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D008297:Male; D008543:Melanins / Q000378:metabolism; D008544:Melanocytes / Q000473:pathology; D016116:Piebaldism / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology*; D010859:Pigmentation Disorders / Q000378:metabolism / Q000503:physiopathology; D011379:Prognosis; D018570:Risk Assessment; D014402:Tuberous Sclerosis / Q000453:epidemiology / Q000378:metabolism / Q000473:pathology; D014607:Uveomeningoencephalitic Syndrome / Q000453:epidemiology / Q000473:pathology; D014849:Waardenburg Syndrome / Q000453:epidemiology / Q000473:pathology
chemical_list: D008543:Melanins
keywords: AA; TSC; VKH; Vogt-Koyanagi-Harada; alopecia areata; poliosis; poliosis circumscripta; tuberous sclerosis; white forelock