BACKGROUND: Temporal triangular alopecia (TTA; also called "congenital triangular alopecia") is a common disorder that is assumed to be congenital. Little is known about its histologic features. OBJECTIVE: Our purpose was to describe four new cases, review the literature, and present histologic features based on vertical and transverse sectioning. METHODS: The history, clinical features, and histologic findings of four patients with TTA are described and the relevant literature reviewed. RESULTS: Lesions of TTA are seldom congenital, and most are best described as lancet-shaped. The "bald spot" contains normal numbers of hairs, although virtually all are vellus or indeterminate follicles. CONCLUSION: Most cases of TTA appear to develop during the first few years of life, and the designation "congenital" is a misnomer. The appearance of alopecia can be best explained as a focal zone of hair miniaturization leading to vellus hair formation.
BACKGROUND: Temporal triangular alopecia (TTA; also called "congenital triangular alopecia") is a common disorder that is assumed to be congenital. Little is known about its histologic features. OBJECTIVE: Our purpose was to describe four new cases, review the literature, and present histologic features based on vertical and transverse sectioning. METHODS: The history, clinical features, and histologic findings of four patients with TTA are described and the relevant literature reviewed. RESULTS: Lesions of TTA are seldom congenital, and most are best described as lancet-shaped. The "bald spot" contains normal numbers of hairs, although virtually all are vellus or indeterminate follicles. CONCLUSION: Most cases of TTA appear to develop during the first few years of life, and the designation "congenital" is a misnomer. The appearance of alopecia can be best explained as a focal zone of hair miniaturization leading to vellus hair formation.
Authors: Hannah M Tully; Jennifer C Dempsey; Gisele E Ishak; Margaret P Adam; Cynthia J R Curry; Pedro Sanchez-Lara; Alasdair Hunter; Karen W Gripp; Judith Allanson; Christopher Cunniff; Ian Glass; Kathleen J Millen; Daniel Doherty; William B Dobyns Journal: Am J Med Genet A Date: 2012-09-10 Impact factor: 2.802