Arc-Shaped Furrow on the Forehead Extending From Linear Alopecia on the Vertex

Abstract

A man in his 50s presented to our dermatology department with an asymptomatic, arcshaped, depressed skin groove on the left side of his forehead, frontal scalp, and vertex area. Localized linear hair loss and hair thinning on the left scalp area were observed. The patient reported that when the lesion had begun to appear, approximately 10 years earlier, he had received 2 doses of intralesional steroid via injection on a small bald patch on the vertex. Thereafter, the lesion gradually progressed to the frontal scalp and eventually made a linear furrow on the left side of his forehead.Physical examination revealed 2 long, curved-line, depressed, alopecic patches on the left side of the vertex and frontal scalp area extending to the left eyebrow (Figure , A and B). The lesions measured (length × width) 7 × 2 cm and 6 × 1 cm, respectively. Dermoscopic examination of the alopecic area revealed several short vellus hairs, yellow dots, and honeycomb hyperpigmentation; however, broken hairs were not seen. The result of a hair pull test was negative. The patient denied any trauma history and had no history of connective tissue disease nor any evidence of systemic involvement, such as arthralgia, photosensitivity, or skin rashes. Skin biopsies were performed on the left side of the vertex and the forehead. Histopathologic findings of the 2 biopsy specimens were identical (Figure, C and D).