INTRODUCTION: Temporal triangular alopecia (TTA) is a nonscarring, noninflammatory, permanent form of alopecia with an unknown etiology, often misdiagnosed as other types of alopecia.
            CASE REPORT: A 27-year-old woman presented with triangular patches of alopecia in the temporal regions, resembling male pattern alopecia. Dermoscopy revealed normal follicular openings. Histopathological analysis showed only vellus follicles, with no telogen or terminal follicles, intact sebaceous glands, and no inflammatory infiltrate.
            DISCUSSION: Dermoscopy is a valuable diagnostic tool, and histopathology may be performed in selected cases. There is no definitive treatment for TTA. Management options include topical minoxidil, hair transplantation, or surgical excision

Ana Letícia Boff

Laura Oliveira Ferreira

Marcelo Balbinot Lucca

Rodrigo Vettorato

Surgical & Cosmetic Dermatology

Directory of Open Access Journals

1APOIO CIENTÍFICO:www.surgicalcosmetic.org.br/ISSN-e 1984-8773Case ReportAuthors:   Marcelo Balbinot Lucca1,2  Laura Oliveira Ferreira1  Ana Letícia Boff3  Rodrigo Vettorato1,31  Irmandandade Santa Casa de Misericórdia de Porto Alegre, Dermatology Department, Porto Alegre (RS), Brazil2  Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre (RS), Brazil3  Private practice, Porto Alegre (RS), Brazil Correspondence:Marcelo Balbinot Lucca   E-mail: marceloblucca@gmail.comFunding source: None.Conflict of interest: None.Submission date: 06/20/2024Final decision: 06/21/2024How to cite this article: Lucca MB, Ferreira LO, Boff AL, Vetto-rato R. Bilateral temporal triangle alo-pecia mimicking male pattern alope-cia in an adult woman: a case report and review of literature. Surg Cosmet Dermatol. 2025;17:e20250380.Bilateral temporal triangle alopecia mimicking male pattern alopecia in an adult woman: a case report and review of literatureAlopecia triangular temporal bilateral simulando alopecia androgenética de padrão masculino em mulher adulta: um relato de caso e revisão de literaturaABSTRACTIntroductIon: Temporal triangular alopecia (TTA) is a nonscarring, noninflammatory, permanent form of alopecia with an unknown etiology, often misdiagnosed as other types of alopecia. case report: A 27-year-old woman presented with triangular patches of alopecia in the temporal regions, resembling male pattern alopecia. Dermoscopy revealed normal follicular openings. Histopatho-logical analysis showed only vellus follicles, with no telogen or terminal follicles, intact sebaceous glands, and no inflammatory infiltrate. dIscussIon: Dermoscopy is a valuable diagnostic tool, and histopathology may be performed in selec-ted cases. There is no definitive treatment for TTA. Management options include topical minoxidil, hair transplantation, or surgical excision.Keywords: Alopecia; Temporal Distribution; Hair Diseases.RESUMOIntrodução: A alopecia triangular temporal é uma alopecia permanente não cicatricial e não inflamatória de etio-logia desconhecida, frequentemente confundida com outros tipos de alopecia. ApresentAção do CAso: Mulher, 27 anos, apresenta placas triangulares de alopecia nas regiões temporais, de distribuição semelhante à alopecia androgenética masculina. A dermatoscopia revelou aberturas foliculares normais. A histopatologia mostrou apenas folículos velos, glândulas sebáceas intactas e ausência de infiltrado inflamatório. dIsCussão: A dermoscopia é uma ferramenta útil para o diagnóstico e a histopatologia pode ser realizada em casos selecionados. Não há tratamento definitivo para alopecia triangular temporal. Opções incluem minoxidil tópico, trans-plante capilar ou exérese.Palavras-chave: Alopecia; Distribuição Temporal; Doenças do Cabelo.DOI: http://www.dx.doi.org/10.5935/scd1984-8773.2025170380Lucca MB, Ferreira LO, Boff AL, Vettorato R.2INTRODUCTIONTemporal triangular alopecia (TTA) is an asymptomatic, localized, nonscarring, and noninflammatory form of perma-nent alopecia with an unknown etiology. Although considered uncommon, it is frequently underdiagnosed.1Typically appearing in childhood, TTA presents as a trian-gular, rounded, or spear-shaped alopecic patch—often singu-lar—in the frontotemporal region, remaining stable throughout life. Dermoscopy and histopathology are valuable tools for dif-ferentiating TTA from other types of alopecia, such as alopecia areata, trichotillomania, traction alopecia, and congenital aplasia cutis.2,3In this report, we present a rare case of bilateral TTA mimicking male pattern alopecia in an adult woman and discuss key considerations for its identification.CASE REPORTA 27-year-old Caucasian female presented to our der-matology practice with a long-standing history of hair thinning in the bilateral temporal region, which began at age 7. The con-dition remained stable over time, with no notable changes or progression, and no involvement of other scalp areas.Previous investigations1 had suggested a possible diagno-sis of trichotillomania, despite the patient denying any hair-pluc-king behavior. She reported no itching, pain, or other associated symptoms. She was in good health and had been continuously using oral contraceptives, with no other ongoing medications.Dermatological examination revealed two triangular--shaped alopecia plaques in the temporal regions, each mea-suring approximately 8 cm in diameter (Figure 1). These plaques contained vellus hairs at the center, surrounded by terminal hairs at the periphery, resembling Hamilton-Norwood type II male pattern alopecia. No erythema or scaling was observed.Dermoscopy (Heine Delta One®) revealed normal fol-licular openings with vellus hairs surrounded by terminal hairs (Figure 2). There were no signs of yellow or black dots, dystro-phic hairs, vascular changes, or decreased follicular openings. The pull test was negative.A skin biopsy was performed on one of the plaques. His-tological analysis showed only vellus follicles, with no telogen or terminal follicles in the alopecic area. Sebaceous glands were in-tact, and there was no inflammatory infiltrate. A single terminal follicle was present at the periphery (Figure 3). These findings, combined with clinical assessment, confirmed a diagnosis of TTA.The patient expressed relief at finally receiving a definiti-ve diagnosis after years of uncertainty. We discussed her progno-sis and the limited therapeutic options with proven efficacy. As a strategy to improve hair density and thickness, oral minoxidil (0.5 mg/day) was prescribed. The patient was satisfied with the diagnostic clarification and agreed to the treatment plan.DISCUSSION AND REVIEW OF LITERATURETTA was first described by Sabouraud in 1905 as “con-genital triangular alopecia,” a term now considered obsolete, as many cases emerge between ages two and nine, while some may present or be diagnosed in adulthood.1,4 In the present case, des-pite the late diagnosis, the onset at age 7 with no subsequent progression was a key factor in confirming the diagnosis.The etiology of TTA remains unknown. While typically sporadic, familial cases suggest an autosomal dominant inheri-tance pattern.1,4 It has also been associated with mosaicism and linked to conditions such as Down syndrome, iris nevus, pig-mentovascular phakomatosis, congenital heart diseases, bone and dental abnormalities, intellectual disability, and aplasia cutis con-genita.1,5,6Figure 1: Triangular-shaped alopecia plaques in the patient's temporal regions, with vellus hairs in the center and terminal hairs at the periphery. The frontotemporal hairline resembles Hamilton-Norwood type II male pattern alopeciaSurg Cosmet Dermatol. 2025;17:e20250380.3black dots, broken hairs, hair tips resembling a broom or brush, split and curled hair trunk stumps, and, in some cases, bleeding spots and pigmentation. During the resting phase, hairless folli-cular openings may be observed.8Aplasia cutis congenita presents clinically as a pink or red atrophic translucent patch, with dermoscopy revealing a translu-cent area devoid of skin appendage openings.2 Sebaceous nevus is characterized by a yellow-orange, velvety plaque, with der-moscopy showing independently distributed and relatively con-sistent yellow-red globular structures unrelated to hair follicles.9 Telogen effluvium manifests as acute or chronic diffuse hair loss, with dermoscopy showing normal hair shaft thickness and signs of shorter regrowing hairs, primarily in the frontal and bitem-poral areas.10 Tinea capitis is characterized by broken hairs, fine scales, spiral or comma-like hair patterns, and dystrophic hairs, with a positive mycological examination typically confirming the diagnosis.2Histopathological assessment is essential, as this condition is frequently misdiagnosed as alopecia areata, especially when it manifests in childhood or early adulthood. The classical his-topathological presentation includes only vellus follicles in the alopecic area, with no telogen follicles, which are prominent in alopecia areata, or terminal follicles with trichomalacia, as seen in trichotillomania. Follicular “stellae” are absent, and normal terminal follicles may be present at the periphery of the lesion. There is no evidence of inflammatory or scarring processes, and the total number of follicles is preserved.3,4 Congenital cases pre-sumably undergo follicular miniaturization in utero, or terminal Although considered rare, with an incidence of 0.11%4 and fewer than 200 reported cases, TTA is believed to be un-derdiagnosed and often mistaken for other forms of alopecia, particularly alopecia areata. TTA is more prevalent in Caucasians and affects both sexes, although men are more frequently af-fected. In over 95% of cases, TTA occurs in the frontotemporal region, with bilateral involvement, as seen in our case, being less common (18.5% of cases).2Dermoscopy plays a critical role in distinguishing TTA from other types of alopecia. Inui et al. proposed the following diagnostic criteria3: 1) triangular or spear-shaped alopecia plaque involving the frontotemporal region; 2) dermoscopy showing normal follicular openings with vellus hairs surrounded by ter-minal hairs; 3) absence of yellow or black dots, dystrophic hairs, and reduced follicular openings on dermoscopy; and 4) minimal hair growth after clinical and dermoscopic confirmation of vel-lus hairs.The primary differential diagnoses include alopecia area-ta, trichotillomania, aplasia cutis congenita, sebaceous nevus, telogen effluvium, and tinea capitis.1,2 Alopecia areata typically presents with a sudden onset of self-limiting alopecic areas, of-ten multiple. Dermoscopic signs include yellow and black dots, broken hairs, exclamation mark hairs, and short vellus hairs. In contrast, dermoscopy of TTA reveals vellus hairs of varying len-gths, whereas alopecia areata only presents with short vellus hairs measuring less than 10 mm.7 Trichotillomania is more common in adolescents and rarely occurs in infants. It predominantly af-fects the parietal and frontal regions, with dermoscopy showing Figure 2: Dermoscopy (Heine Delta One®) of the alopecia plaque shows normal follicular openings with vellus hairs surrounded by terminal hairsFigure 3: Histological analysis reveals follicular units con-taining only vellus follicles, with no inflammatory infiltrate or perifollicular fibrosis (H&E staining, 4× magnification)Lucca MB, Ferreira LO, Boff AL, Vettorato R.4AUTHOR’S CONTRIBUTION:  Marcelo Balbinot Lucca    0000-0001-8395-6742Approval of the final manuscript version; study conception and planning; manuscript drafting and writing; data collection, analysis, and interpre-tation; active participation in research supervision; intellectual contribution to the diagnostic and/or therapeutic approach of the studied cases; critical literature review; critical manuscript review.Laura Oliveira Ferreira    0000-0002-6939-7099Approval of the final manuscript version; data collection, analysis, and interpretation; intellectual contribution to the diagnostic and/or therapeu-tic approach of the studied cases; critical manuscript review.Ana Letícia Boff     0000-0002-5207-0567Approval of the final manuscript version; data collection, analysis, and interpretation; active participation in research supervision; intellectual contribution to the diagnostic and/or therapeutic approach of the studied cases; critical literature review; critical manuscript review.Rodrigo Vettorato    0000-0002-5186-8796Approval of the final manuscript version; study conception and planning, data collection; analysis, and interpretation, active participation in  research supervision; intellectual contribution to the diagnostic and/or therapeutic approach of the studied cases; critical manuscript review.REFERENCES:1. Campos JG, Klein AP, Puga C, Akel PBM, Romero SAR, Pinto GM. Use of dermoscopy in the diagnosis of temporal triangular alopecia. An Bras Dermatol. 2015;90(1):123-5.2. Guan Z, ShiW, Ren M, Bi T, Su H. Clinical and dermatoscopic fea-tures of temporal triangular alopecia in infants. Skin Res Technol. 2023;29:e13294.3. Inui S, Nakajima T, Itami S. Temporal triangular alopecia: trichoscopic diagnosis. J Dermatol. 2012;39:572-4.4. Yamazaki M, Irisawa R, Tsuboi R. Temporal triangular alopecia and a re-view of 52 past cases. J Dermatol. 2010;37:360-2.5. Lederer D, Wilson B, Lefesvre P, Poorten VV, Kirkham N, Mitra D, et al. Atypical findings in three patients with Pai syndrome and literature re-view. Am J Med Genet A. 2012;158A:2899-904.6. Unger R, Alsufyani MA. Bilateral temporal triangular alopecia asso-ciated with phakomatosis pigmentovascularis type iv successfully treated with follicular unit transplantation. Case Rep Dermatol Med. 2011;2011:129541.7. Jha AK, Udayan UK, Roy PK, Amar AKJ, Chaudhary RKP. Dermoscopy of alopecia areata-a retrospective analysis. Dermatol Pract Concept. 2017 Apr 30;7(2):53-57.8. Xingqi Z. Application of dermatoscopy in alopecia. J Clin Dermatol. 2014;43(8): 505-8.9. Martín JM, Montesinos E, Cordero P, Gonzalez V, Ramon D. Trichoscopy features of trichotillomania. Pediatr Dermatol. 2019;36(2):265-267.10. Grover C, Khurana A. Telogen efflfluvium. Indian J Dermatol Venereol Leprol. 2013;79:591–603.11. Sperling L. An atlas of hair pathology with clinical correlations, 2 ed, Editora Informa Healthcare, London, 2012.12. Bang CY, Byun JW, Kang MJ, Yang BH, Song HJ, Shin J, et al. Successful treatment of temporal triangular alopecia with topical minoxidil. Ann Dermatol. 2013;25:387-8.13. Chung J, Sim JH, Gye J, Namkoong S, Hong SP, Kim MH, et al. Successful hair transplantation for treatment of acquired temporal triangular alo-pecia. Dermatol Surg. 2012;38:1404-6.hair formation never occurs, preventing “stellae” formation des-pite the predominance of vellus hairs.11Currently, no effective treatment exists for TTA, and in most cases, therapeutic intervention is unnecessary.2,4,12,13 Providing reassurance about the benign nature of the condition is crucial. In cases of significant aesthetic or emotional distress, hair transplantation and surgical removal of the lesion are the primary treatment options.6,12,13 Bang et al. described the first successful case treated with topical minoxidil,12 though further evidence is required to confirm its efficacy. In our case, minoxi-dil was initiated as a strategy to increase overall hair volume and reduce the visibility of alopecic patches.  l

Bilateral temporal triangle alopecia mimicking male pattern alopecia in an adult female: a case report and review of the literature

http://www.surgicalcosmetic.org.br/Content/imagebank/pdf/v17/en_v17e20250380.pdf

Bilateral temporal triangle alopecia mimicking male pattern alopecia in an adult female: a case report and review of the literature

Abstract

Similar works

Full text

Available Versions

Directory of Open Access Journals