Temporal Triangular Alopecia: Report of FiveCases in Asian Children

Eileen Tan, M.D., Mustika Ng, M.D., and Yoke Chin Giam, M.D.

National Skin Center, Singapore

Abstract: Temporal triangular alopecia (TTA) is a nonscarring alopeciafirst described in 1905. We report five cases of TTA in Asian children andreview the literature.

Temporal triangular alopecia (TTA) is a nonscarringalopecia characterized by unilateral or bilateral, lancet-shaped or oval patches in the frontotemporal scalpregion. It was first described by Sabouraud in 1905 (1).There is a paucity of clinical data on TTA in Asians,although this entity has been well described in theWestern literature (1–9). We report the clinical charac-teristics of five Asian patients diagnosed with this disor-der who were seen in our skin center between 1991 and2000.

CASE REPORTS

The demography and clinical pattern of TTA in fiveAsian children are listed in Table 1. In our series, thediagnosis was based on the static nature and character-istic clinical pattern. Fungal scrapings to rule outdermatophytes were negative in two patients. Themale:female ratio was 3:2. In terms of racial distribution,there were three Chinese children (patient 4 was anadopted child from mainland China), one Indian child(Fig. 1), andone Japanese child. In all cases, the localizedalopecia was first noticed before the age of 2 years. Fourpatients felt that their lesions had been present sincebirth.

All the children have unilateral involvement. Ofinterest is the fact that left frontotemporal alopecia wasmore common thana right side presentation.Thepatternof alopecia conformed to the classic oval, triangular, and

lancet shape. One Chinese boy (patient 2) was misdiag-nosed as alopecia areata by his general practitioner andtreated with intralesional triamcinolone acetonide with-out improvement. There was no association of alopeciaor other skin diseases in the first-degree relatives.

DISCUSSION

TTAwas first described in 1905 by Sabouraud (1). Sincethen there have been several reports published in theWestern literature (2–9). Although this entity has beenwell described, the pathogenesis remains unknown.

We agree with Trakimas et al (2) that the terminology‘‘congenital triangular alopecia’’ is a misnomer.According to previous reports, the pattern of hair lossmay not be triangular and the lesion may appear later(4,7). Approximately 80% of cases were reported to beunilateral and the affected scalp is normal (2,5–7).Familial cases have been previously reported (8,9).

In our series, the diagnosis of TTA was based on itscharacteristic location and the static nature of the lesion.The consistent feature is the focal frontotemporal loca-tion, although variable shapes of alopecic patches havebeen described. All the children have unilateral involve-ment and four patients confirmed that their alopecia waspresent since birth. We postulate that for reasonsunknown, the gradual transition from vellus to terminalhairs did not occur in this area, while the remaining scalphairs gradually changed. Parents could have missed the

Address correspondence to Yoke Chin Giam, M.D., NationalSkin Centre, 1 Mandalay Rd., Singapore 308205.

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lesion, as it may not be apparent until later in childhood.Neither family history nor significant disease associa-tions were noted in the patients and their families.

Abnormal neurologic features have been reported byRuggieri et al (8), however, none were found in ourpatients.

TTA may be confused with other disorders manifes-ted by localized alopecia. The differential diagnosisincludes alopecia areata, trichotillomania, tinea capitis,and traction alopecia. However, in most cases, thediagnosis ofTTAcanbe confidentlymadeon the basis ofthe characteristic clinical features and static nature. Thediagnosis may also be aided by histologic findings ofvellus-like hair follicles (6).

In conclusion, we report five cases of TTA occurringin Asian children. Awareness of the existence of TTA isimportant, as it helps to avoid misdiagnosis and inap-propriate treatment of this benign condition.

REFERENCES

1. Sabouraud R. Manuel elementaire de dermatologietopographique regionale. Paris: Masson and Cie,1905:197.

2. Trakimas C, Sperling LC, Skelton HG, Smith KJ, BukerJL. Clinical and histologic findings in temporal triangularalopecia. J Am Acad Dermatol 1994;31:205–209.

3. Armstrong DKB, Burrows D. Congenital triangular alo-pecia. Pediatr Dermatol 1996;13:394–396.

4. Trakimas CA, Sperling LC. Temporal triangular alopeciaacquired in adulthood. J AmAcad Dermatol 1999;40:842–844.

5. Tosti A. Congenital triangular alopecia. J Am Acad Der-matol 1987;16:991–993.

6. Feuerman EJ. Congenital temporal triangular alopecia.Cutis 1981;28:196–197.

7. Kubba R, Rook A. Congenital triangular alopecia. Br JDermatol 1976;95:657–659.

8. Ruggieri M, Rizzo R, Pavone P, et al. Temporal triangularalopecia in associationwithmental retardation and epilepsyin a mother and daughter. Arch Dermatol 2000;136:426–427.

9. Bargman H. Congenital temporal triangular alopecia. CanMed Assoc J 1984;131:1253–1254.

TABLE 1. Clinical Description of Temporal Triangular Alopecia in Five Asian Children

Case Age at presentation (years) Race Sex Site Family history Associated features Onset of alopecia

1 6 Indian M Left None None Since birth2 18 Chinese M Left None None Since birth3 2 Chinese M Left None Atopic dermatitis Since birth4 6 Chinese (from China) F Left None None 2 years5 0.75 Japanese F Right None None Since birth

Figure 1. Patient 1. A 6-year-old Indian boy with leftfrontotemporal, lancet-shaped temporal triangular alope-cia with its base pointing toward the vertex.

128 Pediatric Dermatology Vol. 19 No. 2 March/April 2002