Trichoscopy in hair disorders in darker skin: An approach to diagnosis

Abstract

Introduction: Trichoscopy is a non-invasive technique that shows promising results in the diagnosis and assessment of response to treatment in various types of alopecias. Besides diagnosing alopecia, it is helpful in choosing an ideal biopsy site. Here authors have attempted to describe trichoscopic findings of healthy scalp and compare hair shaft abnormalities, follicular and interfollicular features and vascular patterns of common non-cicatricial and cicatricial alopecias in skin of color. Summary: Trichoscopy of androgenetic alopecia shows hair diameter diversity, brown and white peripilar sign. Exclamatory hairs and coudability hairs are characteristics of alopecia areata. 'i' hair and pigtail hair indicates good prognosis in alopecia areata. Mace hair sign and burnt matchstick sign are newer findings of trichotillomania. Tinea capitis shows comma hairs, corkscrew hairs. Morse-code like hairs, zigzag hairs and bent hair are specific for tinea capitis. Traction alopecia shows anisotrichosis and hair casts with follicular drop outs in severe disease. Trichoteiromania shows trichoptilosis and broom hairs. Lichen planopilaris (LPP) and discoid lupus erythematosus show 'targetoid' and speckled patterns of blue-grey dots respectively. Perifollicular tubular scaling is characteristic in LPP. Frontal fibrosing alopecia presents as absent follicular openings and follicular plugging. Follicular tufting with starburst fibrotic bands is definitive of folliculitis decalvans. Pseudopelade of Brocq presents with loss of follicular ostia with prominent honeycomb pigmentation.

Keywords

• trichoscopy
• dark skin
• hair shaft
• follicles
• patterns