International Journal of Trichology International Journal of Trichology
 Print this page Email this page Small font sizeDefault font sizeIncrease font size
  Home | About IJT | Editorial board | Search | Ahead of print | Current Issue | Archives | Instructions | Online submission | Subscribe | Advertise | Contact us | Login   

 Table of Contents  
Year : 2015  |  Volume : 7  |  Issue : 2  |  Page : 48-53  

Congenital triangular alopecia

Department of Dermatology, Betsi Cawaladr University Health Board, Rhyl, United Kingdom

Date of Web Publication7-Jul-2015

Correspondence Address:
Vincent Chun Yin Li
Department of Dermatology, Glan Clwyd Hospital, Sarn Lane, Rhyl, LL18 5UJ
United Kingdom
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0974-7753.160089

Rights and Permissions

Congenital triangular alopecia (CTA) also known as temporal triangular alopecia is a benign noncicatricial pattern of hair loss. It typically affects the frontotemporal region and rarely involves the temporoparietal or occipital scalp. It is a nonprogressive disorder that presents as a triangular, oval or lancet-shaped patch of alopecia. CTA can manifest at birth or develop later in life. The exact etiology of this condition remains unknown. Rarely, it may be associated with other disorders such as Down's syndrome and phakomatosis pigmentovascularis. The diagnosis is based on its distinct clinical appearance. Histologically, hair follicles are miniaturized and replaced by sparse vellus hair follicles. Tricoscopy using a polarized light handheld dermatoscope can be a useful diagnostic tool. CTA is often asymptomatic and remains unchanged throughout the life. No treatment is required. Surgical intervention with follicular unit hair transplantation can provide a satisfactory cosmetic result. In this paper, we have identified 126 cases of CTA in the published literature cited on PubMed between 1905 and 2015. From the available evidence, 79% of patients with CTA presented with unilateral hair loss, 18.5% with bilateral involvement and rarely, with occipital alopecia (2.5%). There was no gender predilection. These figures are entirely consistent with previously published data. Physicians should remember to consider CTA as a potential diagnosis in any patient presenting with a nonscarring alopecia in order to avoid unnecessary investigations and treatments.

Keywords: Congenital triangular alopecia, non-scarring alopecia, temporal alopecia

How to cite this article:
Yin Li VC, Yesudian PD. Congenital triangular alopecia. Int J Trichol 2015;7:48-53

How to cite this URL:
Yin Li VC, Yesudian PD. Congenital triangular alopecia. Int J Trichol [serial online] 2015 [cited 2023 May 30];7:48-53. Available from: https://www.ijtrichology.com/text.asp?2015/7/2/48/160089

   Introduction Top

Congenital triangular alopecia (CTA) also known as temporal triangular alopecia, or Brauer nevus, is a benign noncicatricial localized pattern of hair loss. This condition was first described in 1905 by Raymond Sabouraud in his book "Manuel élémentaire de dermatologie topographique réégionale" as "alopecia triangulare congenitale de la temp." [1] As of January 2015, 126 cases have been reported worldwide, as shown in [Table 1]. [2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[],[15],[16],[17],[18],[19],[20],[21],[22],[23],[24],[25],[26],[27],[28],[29],[30],[31],[32],[33],[34],[35],[36],[37],[38],[39],[40],[41],[42],[43],[44],[45],[46],[47],[48],[49],[50] It typically affects the frontotemporal region [Figure 1] and [Figure 2], although there have been reported cases of CTA affecting the temporoparietal [15],[42],[46] and occipital scalp. [36],[37] It is a nonprogressive disorder, which presents as a triangular, oval or lancet-shaped patch of alopecia. [14] CTA may manifest at birth or develop in adulthood. [18] The incidence in the general population is estimated to be 0.11%. [15]
Figure 1: Congenital triangular alopecia affecting the frontotemporal regions bilaterally in an 8-year-old girl (left frontotemporal hair loss shown in this photograph) (This photograph is original courtesy of Dr. Paul Yesudian)

Click here to view
Figure 2: Congenital triangular alopecia affecting the frontotemporal regions bilaterally in an 8-year-old girl (right frontotemporal hair loss shown in this photograph) (This photograph is original courtesy of Dr. Paul Yesudian)

Click here to view
Table 1: Summary of 126 cases of congenital triangular alopecia

Click here to view

   Background Top

Congenital triangular alopecia is usually unilateral but may be bilateral in up to 20% of cases. [14] The condition remains unchanged throughout the life. [8] There is no gender predilection. [28] Most of the reported cases were in Caucasian patients, although CTA has also been documented among Asians [9],[11],[19],[25],[35],[37],[38],[41],[42],[44],[45],[47] and African-Americans. [24] In a published series of 53 patients by Yamazaki et al.[35] in 2010, more than ½ (58.8%) of the cases appeared in patients between the ages of two and nine, while over a third (36.5%) manifest at birth and 3.8% presented in adulthood. From our literature review, 79% of patients with CTA presented with unilateral hair loss while 18.5% of patients had bilateral involvement. About 2.5% consulted with occipital alopecia and 51.6% of the patients were male, versus 48.4% of females. These figures are consistent with previously published data.

Clinical features

Most reported lesions of CTA have been described as lacking any hair, although a few normal terminal or vellus hairs may be evident within the affected patch [Figure 3]. In addition, CTA may not present as a completely bald patch but instead show a centrally localized hair tuft [33] or as small islands of dark hairs. [12]
Figure 3: Triangular patch of hair loss over the left frontotemporal region; normal terminal or vellus hairs may be noted within the affected patch (This photograph is original courtesy of Dr. Paul Yesudian)

Click here to view

Kubba and Rook [8] noted that in the vast majority of cases the area of alopecia was not noted by a child's parents until after 3 years of age. This latency period is attributed to the relatively sparse pelage during the 1 st year of life. [14] Parents may only become aware of the affected patch when it contrasts significantly with the surrounding hair, [8] as the vellus hairs are replaced by terminal hair.


Once considered congenital, CTA appears to be acquired in the majority of individuals. [42] It usually appears sporadically although there have been a small number of familial cases. [5],[20],[22] It has been postulated that CTA may reflect mosaicism [42],[46] and may be inherited as a paradominant trait where a postzygotic loss of the wild type allele in a heterozygote state leads to disease. [51] Others have suggested that CTA may be an ectodermal defect and should be included in the group of epidermal nevi. [22] There is currently no consensus, and the exact etiology of this condition is unclear. There appears to be no obvious phylogenetic or embryological explanation for CTA. [8] Nonetheless, the development of CTA in the 1 st year of life in an area of the scalp that had previously appeared normal is strongly indicative of a localized process of miniaturization of the hair follicles, which produces regression to vellus hair. [29],[45] The stimulus responsible for this irreversible regression remains unknown.


In CTA, normal terminal hair follicles are typically replaced by sparse vellus hair follicles. [7] The total number of hair follicle units are usually in the normal range, [14],[45] except for an isolated case report of a decreased number of hair follicles. [31] The epidermis and dermis are unremarkable [13],[14],[18] with no evidence of an inflammatory infiltrate. [14],[42] However, hair follicles are miniaturized [35],[45],[46] with an increased proportion of vellus or indeterminate hairs. [14],[18],[45],[50] This may be due to abnormalities in follicle morphogenesis and supports the idea that CTA is a form of a hamartomatous mosaic disease possibly involving an abnormal, local, epithelial-mesenchymal interaction. [35] Collagen bundles and vessels in the dermis shows no abnormalities; sweat glands and sebaceous glands are normal in size and number. [35] Bacterial and fungal stains are negative. [18]


The diagnosis of CTA is mainly clinical and based on its distinct clinical appearance and location. It is not dependent on histology. Sometimes, CTA may be misdiagnosed as other types of localized alopecia that present with a small, round or oval hairless patch in atypical locations on the scalp. Common differential diagnoses, which should be considered, are listed in [Table 2].
Table 2: Differential diagnoses of congenital triangular alopecia

Click here to view

A classification system for the diagnosis of CTA proposed by Inui et al.[38] emphasized the importance of four main clinical features. (1) A triangular or spear-shaped patch of hair loss located over the frontotemporal region of the scalp; (2) normal hair follicles with vellus-type hairs surrounded by a normal terminal hair area; (3) absence of fractured or exclamation mark hairs and no black or yellow dots with a preserved follicular orifice; and (4) lack of significant hair growth 6 months after confirming the presence of vellus hairs on dermoscopy.


Congenital triangular alopecia is associated with other disorders in up to 15% of cases [50] and may occur as a key feature in a multiple malformation syndrome. [28] Common associated features are listed in [Table 3] and syndromes in [Table 4].
Table 3: Reported disorders presenting in association with congenital triangular alopecia

Click here to view
Table 4: Reported syndromic associations

Click here to view


Trichoscopic examination using a handheld polarized light dermatoscope has emerged as a helpful diagnostic tool as it can help to elucidate clinical signs that cannot be recognized by the naked eye. [48] Follicular features of CTA include short vellus hairs with varying hair length diversity, as well as white hairs in the absence of diagnostic features for other types of localized alopecia. [48] The presence of epidermal scaling, as well as interfollicular features such as arborizing red lines and a honeycomb pigment pattern, may also be useful clues. [48] Vellus hairs are a highly sensitive but not specific marker for CTA. [48] A study by Shim et al.[52] demonstrated clustered short vellus hairs without other specific findings. Videodermoscopy has also been used. [53] The hair pull test was negative in all reported cases. [28],[46],[48]


Congenital triangular alopecia is often asymptomatic and remains unchanged throughout the life; it is likely that many patients do not consult a physician for this particular condition. [13] It is viewed as a permanent condition with no specific treatment necessary except for cosmetic reasons. The exact nature of CTA should be explained to parents so that they can avoid fruitless investigations or harmful treatments. [28] Medical treatment of CTA with topical or intralesional corticosteroids have not proved effective. [29] Bang et al.[45] reported a successful case of transient improvement with the use of 3% topical minoxidil in a 1-year-old child. Terminal hair growth was observed. Unfortunately, hair regrowth was not sustained following the cessation of treatment. Hair restoration surgery using follicular unit transplantation or surgical excision may provide patients with a satisfactory cosmetic result. [29],[32],[40],[41],[45] Long-term sustained benefits have been reported after 6 years of follow-up. [40]

   Conclusion Top

Congenital triangular alopecia is likely underreported and in reality, not an uncommon disorder. It may be underdiagnosed due to diagnostic confusion with other types of nonscarring alopecia [50] and under reported due to its asymptomatic and nonprogressive nature. [42] Future advances in molecular and genetic studies will help to reveal the exact etiology this condition. [35] Unnecessary treatments such as topical corticosteroids may be avoided; to achieve this, one must remember to consider CTA as a possible diagnosis in any patient presenting with a nonscarring alopecia.

   References Top

Sabouraud R. A Manual of Regional Topographical Dermatology. Paris: Masson; 1905. p. 197.  Back to cited text no. 1
Galewsky E. Handbuch Der Haut Und Geshlechtskrankheiten. Vol. 13. Berlin: Springer, 1932. p. 192.  Back to cited text no. 2
Sabouraud R. Diagnosis and Treatment of Scalp Disorders. Paris: Masson; 1932. p. 22-3.  Back to cited text no. 3
Canizares O. Alopecia triangulariscongenitalis. Report of a case. Arch Derm Syphilol 1941;44:1106-7.  Back to cited text no. 4
Degos R, Rabut R. Congenital Angular Alopecia of the Temple. Bull Soc Franc Dermatol Syphil 1949;5:487.  Back to cited text no. 5
Muller SA. Alopecia: Syndromes of genetic significance. J Invest Dermatol 1973;60:475-92.  Back to cited text no. 6
Minars N. Congenital temporal alopecia. Arch Dermatol 1974;109:395-6.  Back to cited text no. 7
Kubba R, Rook A. Congenital triangular alopecia. Br J Dermatol 1976;95:657-9.  Back to cited text no. 8
Kawamura T. Alopecia in infancy. Hifubyoh Shinryoh 1979;1:923-6.  Back to cited text no. 9
Fuerman EJ. Congenital temporal triangular alopecia. Cutis 1981;28:196-7.  Back to cited text no. 10
Kikuchi I, Okazaki M. Congenital temporal alopecia in phakomatosis pigmentovascularis. J Dermatol 1982;9:485-7.  Back to cited text no. 11
Bargman H. Congenital temporal triangular alopecia. Can Med Assoc J 1984;131:1253-4.  Back to cited text no. 12
Tosti A. Congenital triangular alopecia. Report of fourteen cases. J Am Acad Dermatol 1987;16:991-3.  Back to cited text no. 13
Trakimas C, Sperling LC, Skelton HG 3 rd , Smith KJ, Buker JL. Clinical and histologic findings in temporal triangular alopecia. J Am Acad Dermatol 1994;31:205-9.  Back to cited text no. 14
García-Hernández MJ, Rodríguez-Pichardo A, Camacho F. Congenital triangular alopecia (Brauer nevus). Pediatr Dermatol 1995;12:301-3.  Back to cited text no. 15
Armstrong DK, Burrows D. Congenital triangular alopecia. Pediatr Dermatol 1996;13:394-6.  Back to cited text no. 16
Kenner JR, Sperling LC. Pathological case of the month. Temporal triangular alopecia and aplasia cutis congenita. Arch Pediatr Adolesc Med 1998;152:1241-2.  Back to cited text no. 17
Trakimas CA, Sperling LC. Temporal triangular alopecia acquired in adulthood. J Am Acad Dermatol 1999;40:842-4.  Back to cited text no. 18
Kim HJ, Park KB, Yang JM, Park SH, Lee ES. Congenital triangular alopecia in phakomatosis pigmentovascularis: Report of 3 cases. Acta Derm Venereol 2000;80:215-6.  Back to cited text no. 19
Ruggieri M, Rizzo R, Pavone P, Baieli S, Sorge G, Happle R. Temporal triangular alopecia in association with mental retardation and epilepsy in a mother and daughter. Arch Dermatol 2000;136:426-7.  Back to cited text no. 20
Akan IM, Yildirim S, Avci G, Aköz T, Karadayi N. Bilateral temporal triangular alopecia acquired in adulthood. Plast Reconstr Surg 2001;107:1616-7.  Back to cited text no. 21
Patrizi A, Morrone P, Fiorentini C, Bianchi T. An additional familial case of temporal triangular alopecia. Pediatr Dermatol 2001;18:263-4.  Back to cited text no. 22
Elmer KB, George RM. Congenital triangular alopecia: A case report and review. Cutis 2002;69:255-6.  Back to cited text no. 23
Erickson Q, Yanase D, Perry V. Temporal triangular alopecia: Report of an African-American child with TTA misdiagnosed as refractory tinea capitis. Pediatr Dermatol 2002;19:129-31.  Back to cited text no. 24
Tan E, Ng M, Giam YC. Temporal triangular alopecia: Report of five cases in Asian children. Pediatr Dermatol 2002;19:127-8.  Back to cited text no. 25
Park SW, Choi YD, Wang HY. Congenital triangular alopecia in association with congenital heart diseases, bone and teeth abnormalities, multiple lentigines and café-au-lait patches. Int J Dermatol 2004;43:366-7.  Back to cited text no. 26
Bordel-Gómez MT. Congenital triangular alopecia associated with Down's syndrome. J Eur Acad Dermatol Venereol 2008;22:1506-7.  Back to cited text no. 27
León-Muiños E, Monteagudo B, Labandeira J, Cabanillas M. Bilateral congenital triangular alopecia associated with congenital heart disease and renal and genital abnormalities. Actas Dermosifiliogr 2008;99:578-9.  Back to cited text no. 28
Jiménez-Acosta F, Ponce I. Hair transplantation in triangular temporal alopecia. Actas Dermosifiliogr 2009;100:913-5.  Back to cited text no. 29
Lee KC, Chamlin SL. A 14-year-old girl with a patch of hair loss. Temporal triangular alopecia. Pediatr Ann 2009;38:646, 648-9.  Back to cited text no. 30
Silva CY, Lenzy YM, Goldberg LJ. Temporal triangular alopecia with decreased follicular density. J Cutan Pathol 2010;37:597-9.  Back to cited text no. 31
Wu WY, Otberg N, Kang H, Zanet L, Shapiro J. Successful treatment of temporal triangular alopecia by hair restoration surgery using follicular unit transplantation. Dermatol Surg 2009;35:1307-10.  Back to cited text no. 32
Assouly P, Happle R. A hairy paradox: Congenital triangular alopecia with a central hair tuft. Dermatology 2010;221:107-9.  Back to cited text no. 33
Bonifazi E. Congenital triangular alopecia with a tuft of normal hair inside. Eur J Pediatr Dermatol 2010;20:273.  Back to cited text no. 34
Yamazaki M, Irisawa R, Tsuboi R. Temporal triangular alopecia and a review of 52 past cases. J Dermatol 2010;37:360-2.  Back to cited text no. 35
Bonifazi E. Hypotrichotic nevus (congenital triangular alopecia). Eur J Pediatr Dermatol 2011;21:57.  Back to cited text no. 36
Gupta LK, Khare A, Garg A, Mittal A. Congenital triangular alopecia: A close mimicker of alopecia areata. Int J Trichology 2011;3:40-1.  Back to cited text no. 37
Inui S, Nakajima T, Itami S. Temporal triangular alopecia: Trichoscopic diagnosis. J Dermatol 2012;39:572-4.  Back to cited text no. 38
Turk BG, Turkmen M, Tuna A, Karaarslan IK, Ozdemir F. Phakomatosis pigmentovascularis type IIb associated with Klippel-Trénaunay syndrome and congenital triangular alopecia. J Am Acad Dermatol 2011;65:e46-9.  Back to cited text no. 39
Unger R, Alsufyani MA. Bilateral temporal triangular alopecia associated with phakomatosis pigmentovascularis type IV successfully treated with follicular unit transplantation. Case Rep Dermatol Med 2011;2011:129541.  Back to cited text no. 40
Chung J, Sim JH, Gye J, Namkoong S, Hong SP, Kim MH, et al. Successful hair transplantation for treatment of acquired temporal triangular alopecia. Dermatol Surg 2012;38:1404-6.  Back to cited text no. 41
Kudligi C, Bhagwat PV, Eshwarrao MS, Tandon N. Giant congenital triangular alopecia mimicking alopecia areata. Int J Trichology 2012;4:51-2.  Back to cited text no. 42
Lederer D, Wilson B, Lefesvre P, Poorten VV, Kirkham N, Mitra D, et al. Atypical findings in three patients with Pai syndrome and literature review. Am J Med Genet A 2012;158A: 2899-904.  Back to cited text no. 43
Lew BL, Kim JH, Sim WY. Clinicopathologic observation of temporal triangular alopecia. J Am Acad Dermatol 2012;66:AB97.  Back to cited text no. 44
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.  Back to cited text no. 45
Tas B, Pilanci Ö, Basaran K. Congenital temporal triangular alopecia: A typical Brauer nevus. Acta Dermatovenerol Alp Pannonica Adriat 2013;22:93-4.  Back to cited text no. 46
Jamwal A, Sharma SD. Congenital triangular alopecia. Indian Pediatr 2014;51:511.  Back to cited text no. 47
Karadag Köse O, Güleç AT. Temporal triangular alopecia: Significance of trichoscopy in differential diagnosis. J Eur Acad Dermatol Venereol 2014;  [doi: 10.1111/jdv.12656].  Back to cited text no. 48
Lacarrubba F, Micali G. Congenital triangular alopecia. BMJ Case Rep 2014; [doi: 10.1136/bcr-2013-202918].  Back to cited text no. 49
Oliveira LC, Miranda AR, Pinto SA, Ianhez M. Case for diagnosis. Alopecia areata and congenital triangular alopecia. An Bras Dermatol 2014;89:353-5.  Back to cited text no. 50
Happle R. Congenital triangular alopecia may be categorized as a paradominant trait. Eur J Dermatol 2003;13:346-7.  Back to cited text no. 51
Shim WH, Jwa SW, Song M, Kim HS, Ko HC, Kim BS, et al. Dermoscopic approach to a small round to oval hairless patch on the scalp. Ann Dermatol 2014;26:214-20.  Back to cited text no. 52
Iorizzo M, Pazzaglia M, Starace M, Militello G, Tosti A. Videodermoscopy: A useful tool for diagnosing congenital triangular alopecia. Pediatr Dermatol 2008;25:652-4.  Back to cited text no. 53


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1], [Table 2], [Table 3], [Table 4]

This article has been cited by
1 Regrowth of hair in congenital triangular alopecia induced by sublingual minoxidil
Karlijn L. J. Clarysse, Rodney Sinclair
Australasian Journal of Dermatology. 2023;
[Pubmed] | [DOI]
2 What is your diagnosis?
MohamedH.M El-Komy
Journal of the Egyptian Women's Dermatologic Society. 2023; 20(2): 146
[Pubmed] | [DOI]
3 Localized hair loss in infancy: a review
Paige L. McKenzie, Leslie Castelo-Soccio
Current Opinion in Pediatrics. 2021; 33(4): 416
[Pubmed] | [DOI]
4 Clinical and molecular evaluation of 13 Brazilian patients with Gomez-López-Hernández syndrome
Eduardo Perrone, Ana Beatriz Alvarez Perez, Vânia D'Almeida, Claudia Berlim Mello, Marcela Amaral Avelino Jacobina, Rafael Maffei Loureiro, Stênio Burlin, Michele Migliavacca, Luiza Amaral Virmond, Carla Graziadio, José Luiz Pedroso, Elaine Lustosa Mendes, Israel Gomy, Nara Lygia Macena Sobreira
American Journal of Medical Genetics Part A. 2021; 185(4): 1047
[Pubmed] | [DOI]
5 Haartransplantation bei Frauen
Andrea Sauter
Journal für Ästhetische Chirurgie. 2021; 14(3): 92
[Pubmed] | [DOI]
6 Alopécie triangulaire congénitale de Sabouraud
M.-H. Jégou, P. Assouly
Annales de Dermatologie et de Vénéréologie - FMC. 2021; 1(5): 322
[Pubmed] | [DOI]
7 Hair transplantation: Basic overview
Francisco Jimenez, Majid Alam, James E. Vogel, Marc Avram
Journal of the American Academy of Dermatology. 2021; 85(4): 803
[Pubmed] | [DOI]
8 Alopécie de l’enfant
K. Legal, P. Plantin
Journal de Pédiatrie et de Puériculture. 2021; 34(3): 130
[Pubmed] | [DOI]
9 Alopecia en el niño
K. Legal, P. Plantin
EMC - Pediatría. 2020; 55(4): 1
[Pubmed] | [DOI]
10 Alopecia en el niño
K. Legal, P. Plantin
EMC - Dermatología. 2020; 54(3): 1
[Pubmed] | [DOI]
11 Aplasia cutis congenita of the scalp: Histopathologic features and clinicopathologic correlation in a case series
Maximilian Gassenmaier, Hans Bösmüller, Gisela Metzler
Journal of Cutaneous Pathology. 2020; 47(5): 439
[Pubmed] | [DOI]
12 Hair Loss
Reese L. Imhof, Dawn Marie R. Davis, Megha M. Tollefson
Pediatrics in Review. 2020; 41(11): 570
[Pubmed] | [DOI]
13 Alopecia Areata vs Trichotillomania. Differential Diagnosis According to Trichoscopy
Aida G. Gadzhigoroeva
Current Pediatrics. 2020; 19(6): 509
[Pubmed] | [DOI]
14 Alopecia - overview, causes and current treatment options
Emanuel Marques, Milena Tanczosová, Monika Arenbergerová
Dermatologie pro praxi. 2020; 14(3): 124
[Pubmed] | [DOI]
15 Congenital alopecia of eyebrow
Deepak Jakhar, Chander Grover
Indian Journal of Dermatology, Venereology and Leprology. 2018; 84(6): 743
[Pubmed] | [DOI]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
    Article Figures
    Article Tables

 Article Access Statistics
    PDF Downloaded112    
    Comments [Add]    
    Cited by others 15    

Recommend this journal