title: Temporal triangular alopecia and a review of 52 past cases.
abstract: Temporal triangular alopecia (TTA) is a circumscribed, non-cicatricial form of alopecia confined to the frontotemporal region. The patient, a 15-year-old boy, was noticed at birth to have an alopecial area, sized 1.5 cm x 2.5 cm, in the right temporal region. Microscopic examination revealed miniaturized hair follicles accompanied by differentiated sebaceous glands. We have provided a synopsis of the past 52 cases. Of the 53 cases of TTA including our case, more than half (55.8%) were detected in childhood between the ages of 2 and 9 years, while 36.5% were detected at birth and only 3.8% (only two cases) in adulthood. There were three familial cases. Several congenital diseases were associated with the condition, for example, phakomatosis pigmentovascularis, Down syndrome and Dandy-Walker malformation. This information suggests that TTA can be recognized as a hamartomatous mosaic disease.
authors.affiliation: Department of Dermatology, Tokyo Medical University, Tokyo, Japan. msyzk@tokyo-med.ac.jp
authors.forename: Masashi
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Ryokichi
authors.initials: R
authors.lastname: Irisawa
authors.forename: Ryoji
authors.initials: R
authors.lastname: Tsuboi
mesh_terms: D000293:Adolescent; D000328:Adult; D000505:Alopecia / Q000151:congenital* / Q000235:genetics / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D003616:Dandy-Walker Syndrome / Q000150:complications; D004314:Down Syndrome / Q000150:complications; D005260:Female; D018859:Hair Follicle / Q000002:abnormalities*; D006222:Hamartoma / Q000151:congenital* / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009030:Mosaicism; D055815:Young Adult