Clinical and dermatoscopic features of temporal triangular alopecia in infants.

OBJECTIVE: To summarize the clinical and dermatoscopic features of temporal triangular alopecia in infants and explore the clinical significance of dermatoscopy in the diagnosis of triangular alopecia temporalis in infants. METHODS: A retrospective analysis was performed on 20 children with temporal triangular alopecia diagnosed in the dermatology clinic of Tianjin Children's Hospital from January 2015 to December 2021. Dermatoscopy was performed on all children, and images were collected. RESULTS: The clinical features of 20 children were 15 males and five females, all of which were born immediately after birth; There were eight cases (40%) in the left temporal region, 10 cases (50%) in the right temporal region, one case (5%) in the head region, and one case (5%) in the occipital region; 19 cases were single (95%), one case was multiple (5%); There were 21 skin lesions, 15 triangular lesions (71.4%), four quasi-circular lesions (19%), and two lance-shaped lesions (9.5%). Trichoscopic features: The hair follicle opening in all skin lesions is normal, and the hair follicle opening can be seen with fluffy hair (vellus hair). The vellus hair is evenly distributed, and the length is diverse (both short and long vellus hair exist in the same hair loss area). There are 14 cases of white vellus hair (70%), five cases of white spots (25%), one case of honeycomb pigment pattern (5%), and one case of vascular dilation pattern (5%). CONCLUSION: Temporal triangular alopecia in infants has typical clinical and dermatoscopic characteristics, and the dermatoscopy can provide clinical basis for its diagnosis and differential diagnosis.

Transient Treatment Response of Platelet-rich Plasma Injection for Temporal Triangular Alopecia: A Case Report with Dermoscopic Examination Follow-up.

Temporal triangular alopecia (TTA) is congenital anomalies that usually develops in childhood, with rarely acquired cases in adults. TTA shares common clinical, dermoscopic, and histologic features of characterized vellus hair formation change, similar to androgenetic alopecia (AGA). Whereas, platelet-rich plasma (PRP) with multiple growth factors can provide treatment efficacy in AGA. Due to limited treatment for TTA, such as topical minoxidil, complete surgical excision, and hair transplantation, the multiple growth factors in PRP is thus postulated to be also effective for TTA treatment, just as in AGA. We present a case of TTA with unsatisfactory treatment outcome of only increased number and thickness of vellus hair by dermoscopic examination follow-up after the 5-session PRP injection and only transient response for 6 months. Unlike, AGA, the PRP injection might not consequently be a suitable treatment option for TTA. Nonetheless, further studies should be performed to investigate the potential treatment modality for TTA.

Congenital Triangular Alopecia - A Case Report.

Congenital triangular alopecia also known as temporal triangular alopecia or Brauer nevus may be present at birth or acquired during the first decade of life. It can present as triangular, oval, or lancet-shaped patch of alopecia. It may be misdiagnosed as alopecia areata, traction alopecia, trichotillomania, tinea capitis, and aplasia cutis congenita. Histopathological features and dermoscopic features help in its diagnosis. There is no effective treatment for it and, in most cases, there is no need for therapeutic intervention. Therapeutic modalities include topical minoxidil, surgical excision, and hair transplantation.