先天性三角形脱毛症の1例

A Case of Congenital Triangular Alopecia

はじめに

　先天性三角形脱毛症は先天性非瘢痕性脱毛症の一型であり，側頭部に多く発症するため側頭部三角形脱毛症ともいわれている。1906年にSabouraud 1）によって初めて報告された古い疾患概念であるが，時々耳にする疾患である。

　今回われわれは，先天性三角形脱毛症の1例を経験した。最近の文献をレビューし，考察を加え報告する。

　A 13-year-old boy presented to our hospital with an alopecic scalp lesion on the right temporal area. The lesion had first been noted at his birth, and the alopecial area had been treated since then.

　A dermatologist had continued to administer topical steroids to treat alopecia areata, but since this provided no improvement, the patient underwent excisional surgery at 13 years of age. Based on the pathology results and his medical history, he was diagnosed with congenital triangular alopecia （CTA）.

　CTA, also known as temporal triangular alopecia, is a somewhat rare disease. To the best of our knowledge, only 175 cases of CTA have been reported to date, and its etiology remains unclear. Although CTA may be diagnosed before surgery based on a patient’s medical history and dermoscopic findings, noninvasive treatments are often ineffective despite being conducted over a long period of time, due to the lack of recognition of this disease. Since topical steroids do not improve CTA, excision is performed when requested by patients. Simple suturing, rotational skin valve surgery, and hair transplantation have been performed depending on the severity of the alopecia.

　We hope that clinicians’ recognition of CTA will increased with the further accumulation of cases.