Trichoscopy in Alopecia: Distinguishing Scarring and Non-Scarring Hair Loss with Case-Based Findings

Conclusions

• Trichoscopy is a valuable first-line tool for diagnosing hair loss because it can distinguish normal scalp anatomy from scarring and non-scarring alopecias.
• Preserved follicular openings and an intact honeycomb pigment network favor non-scarring alopecia, whereas loss of follicular ostia, white patches, and asterisk-like macules indicate scarring alopecia.
• Alopecia areata is suggested by black dots, broken hairs, exclamation point hairs, yellow dots, and regrowing pigtail or circle hairs.
• The pattern of trichoscopic findings in alopecia areata can help estimate disease activity, with broken hairs and exclamation point hairs indicating active disease and pigtail or vellus regrowth signaling recovery.
• Tinea capitis can be recognized by atypical hair-shaft shapes such as comma, corkscrew, zigzag, and Morse code hairs, often with scale or white sheath.
• Trichoscopy can guide empiric treatment choice in tinea capitis before cultures return, with Trichophyton features favoring terbinafine and Microsporum features favoring griseofulvin.
• Discoid lupus erythematosus presents trichoscopically with loss of the honeycomb pattern, keratotic plugs, follicular red dots, branching vessels, and blue-gray dots.
• Traction alopecia shows early signs such as hair casts and preserved vellus hairs, while chronic traction can progress to scarring and be marked by the flambeau sign.
• Frontal fibrosing alopecia and CCCA are scarring alopecias that can be distinguished from androgenetic alopecia by loss of vellus hairs, peripollicular scale, and follicular fibrosis patterns.
• Psoriasis of the scalp is suggested by white or silvery scale, erythema, twisted red loop vessels, and red dots, while seborrheic dermatitis more often shows yellow waxy scale and lacks red dots.
• Androgenetic alopecia is characterized by hair miniaturization, reduced shaft thickness, increased diameter variability, and fewer hairs per follicular unit.
• UV-induced fluorescence trichoscopy appears to improve visualization of active follicular openings and may help in both diagnosis and monitoring of alopecia and tinea capitis.
• Showing trichoscopy images to patients can improve understanding, reinforce counseling, and support adherence to hairstyle or treatment recommendations.