The value of dermoscopy in diagnosing eyebrow loss in patients with alopecia areata and frontal fibrosing alopecia

Introduction Alopecia areata and frontal fibrosing alopecia are common causes of eyebrow loss (madarosis). Objective Assessment of trichoscopic markers of eyebrow loss in alopecia areata and frontal fibrosing alopecia. Materials and methods The analysis included 50 patients with scalp alopecia areata with madarosis, 50 patients with scalp frontal fibrosing alopecia with madarosis and 50 healthy controls. In every case, trichoscopy of the eyebrow area was performed. Results Empty follicular and eccrine duct openings were observed in all patients and presented predominantly as yellow dots. Exclamation mark hairs were only detected in patients with alopecia areata (30%). Tapered hairs, broken hair, black dots and Pohl-Pinkus constrictions were observed in 14%, 36%, 26% and 4% of patients with alopecia areata, respectively, 4%, 16%, 2% and 0% of patients with frontal fibrosing alopecia, respectively, and they were not present in healthy controls. Dystrophic hairs and whitish areas were observed only in patients with frontal fibrosing alopecia (28% and 32%, respectively). Eyebrow regrowth in distinct directions was present in 32% of patients with frontal fibrosing alopecia, 8% of patients with alopecia areata and 4% of healthy controls. Diffuse erythema was detected in 60% of patients with alopecia areata and frontal fibrosing alopecia and 56% of healthy controls. Vellus hairs and upright regrowing hairs were observed in patients with alopecia areata (62% and 58%, respectively), frontal fibrosing alopecia (60% and 84%, respectively) and healthy controls (100% and 100%, respectively). Conclusion Trichoscopy of the eyebrow area is useful in diagnosing patients with isolated eyebrow loss. The most characteristic trichoscopic features of eyebrow loss in alopecia areata include exclamation mark hairs, tapered hairs, broken hairs and black dots. Frontal fibrosing alopecia of the eyebrows is characterized by the presence of dystrophic hairs, white areas and eyebrow regrowth in distinct directions.