Giant congenital triangular alopecia mimicking alopecia areata

Alopecia Triangular congénita temporal en edad pediátrica. A propósito de un caso

Se presenta el caso de una niña de 9 años de edad, valorada en el servicio de Dermatología provincial por ausencia de cabello presente desde el nacimiento. Se evalúa en conjunto y se concluye clínicamente como una Alopecia Triangular Congénita Temporal, sin necesidad de biopsia cutánea. Esta entidad es un trastorno de prevalencia desconocida, aunque quizá más frecuente de lo que podamos pensar, pero que en ocasiones puede constituir motivo de consulta al pediatra y/o al dermatólogo. Es una forma de Alopecia no cicatricial. Es necesario conocerla para evitar tratamientos y pruebas innecesarias para su diagnóstico por la gran similitud con otras dermatosis.

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.

Congenital Triangular Alopecia

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.