RESUMO
Background: Trichoscopy is an office tool used in the diagnosis of alopecia but its utility has not been assessed. Objectives: To compare the trichoscopic characteristics of different types of alopecia, identify features of diagnostic value, and to determine the utility of trichoscopy in the diagnosis of alopecia. Methods: A descriptive cross‑sectional study was performed in patients with alopecia. After clinical assessment and relevant investigations, trichoscopy was performed using a non‑polarized trichoscope (×10). The utility of trichoscopy in difficult cases of alopecia was assessed statistically. Results: One hundred and twenty patients of alopecia (90 non-cicatricial, 30 cicatricial) were recruited. The diagnosis was made on the basis of a detailed history and clinical examination, and confirmed by biopsy and relevant investigations in difficult cases. Yellow dots (63.3%) were the most common trichoscopic feature followed by thin hair (40.8%). Among the 21 difficult cases of alopecia, trichoscopy was diagnostic in 19 (90.5%). Statistically significant features on intergroup comparison included black dots (Fischer’s exact test, P < 0.001), cadaverized hair (P = 0.024), exclamation mark hair (P < 0.001) in alopecia areata; diameter diversity more than 20% (P < 0.001) and thin hair (P < 0.001) in androgenetic alopecia; broken hair of different lengths (P < 0.001), frayed hair (P < 0.001), split ends (P < 0.001) in trichotillomania; comma hair (P < 0.001) in tinea capitis and arborizing blood vessels in discoid lupus erythematosus (P = 0.012). Limitations: The small number of patients in some types of alopecia was a limiting factor. Conclusions: Trichoscopy is useful in the differential diagnosis of alopecia. Among the various trichoscopic findings, those of diagnostic value were identified.