HairAdvanced · 3 min read

Trichoscopy & Hair Disorders

Yellow dots, vellus, peripilar signs, the trichoscopic toolkit for AGA, alopecia areata, scarring alopecia and the LPP/FFA spectrum.

By Dr. Yehonatan KaplanPublished Updated

In brief

Trichoscopy is dermoscopy of the scalp and hair. It separates non-scarring (alopecia areata, AGA, telogen effluvium) from scarring (LPP/FFA, DLE, CCCA) alopecia at the chair side, often without biopsy. Modern systemic AGA treatment (oral minoxidil, dutasteride mesotherapy) and the LPP/FFA recognition algorithm are the two AAD 2026 highlights.

Clinical content

01Androgenetic alopecia (AGA): hair shaft diversity (caliber variation >20%), yellow dots, peripilar brown halos, increased vellus hairs centrally on the vertex. Frontal hairline often spared in male pattern.

02Telogen effluvium: short upright regrowing hairs without other features; hair pull positive at multiple sites.

03Alopecia areata: 'exclamation mark' hairs, black dots (broken hairs), yellow dots (empty follicles), tapered hair shafts. Active AA shows tapering at root.

04Lichen planopilaris (LPP): perifollicular scale, perifollicular erythema, hair tufting, loss of follicular ostia (white dots replacing follicles).

05Frontal fibrosing alopecia (FFA): same LPP signs but distributed at the frontotemporal hairline + eyebrow loss + glabellar red dots. Lonely hair sign (isolated hair within scarred zone) is pathognomonic.

06Discoid lupus on scalp: perifollicular keratin plugs + telangiectasias + white scarring patches, scattered red dots within follicles.

07CCCA (Central Centrifugal Cicatricial Alopecia): peripilar grey-white halo + pinpoint white dots + variable shaft caliber; distinguishes from AGA only on biopsy.

08Treatment innovations 2024-2026. Low-dose oral minoxidil (1.25-5 mg/day) is now first or second line for AGA after topical failure. Dutasteride mesotherapy and oral dutasteride (off-label) used in non-responders. JAK inhibitors (baricitinib, ritlecitinib) FDA-approved for severe alopecia areata.

Key dermoscopic features

Hair shaft diversity (>20% caliber variation)
Androgenetic alopecia.
Yellow dots (empty follicles)
AA, AGA, FFA.
Peripilar brown halo
Early AGA.
Exclamation mark hairs
Alopecia areata.
Black dots (broken hairs)
AA active phase or trichotillomania.
Perifollicular scale + erythema
Lichen planopilaris.
Loss of follicular ostia (white dots)
Scarring alopecia (LPP/FFA/DLE/CCCA).
Lonely hair sign
Pathognomonic for FFA.
Red dots within follicles
DLE on scalp.
Perifollicular grey-white halo + variable caliber
CCCA.

High yield clinical points12 pearls in 5 groups

Recognition & pattern analysis

7 points
20%
Caliber variation = AGA. >20% hair-shaft diameter variation in the affected zone is the trichoscopic hallmark of AGA.
2
Yellow dots are non-specific. Seen in AA, AGA, and FFA, useful but not diagnostic alone.
3
Exclamation marks = active AA. Tapered, broken hairs with darker tip, pathognomonic for active alopecia areata.
4
Perifollicular = scarring. Perifollicular erythema and scale separate scarring (LPP) from non-scarring (AA, AGA) alopecia.
5
Lonely hair = FFA. Isolated hair within an otherwise scarred frontotemporal zone is pathognomonic for frontal fibrosing alopecia.
6
Eyebrow loss precedes scalp in FFA. Always trichoscope eyebrows in suspected FFA; eyebrow loss can predate scalp findings by years.
10%
Hair pull test still matters. Pull from 3 sites with 60+ hairs; >10% telogen on scalp pull is significant, combine with trichoscopy.

Management & treatment

2 points
1
Loss of follicular ostia = irreversible. White dots replacing follicular openings means scarring; treatment goal becomes halting progression, not regrowth.
2
Low-dose oral minoxidil for AGA. 1.25-5 mg/day is now standard second-line (or first-line in topical-intolerant patients) for AGA in both sexes.

Pitfalls & mimics

1 point
1
CCCA mimics AGA. CCCA in early stages can look like AGA on trichoscopy; perifollicular grey-white halo + biopsy when in doubt, especially in Black women age 30-50.

When to biopsy

1 point
1
DLE scalp = follicular plugs + red dots. Perifollicular keratin plugs + telangiectasias with red dots inside follicles, biopsy and start hydroxychloroquine.

Follow-up & monitoring

1 point
1
JAK inhibitors for severe AA. Baricitinib (adults) and ritlecitinib (≥12) are FDA-approved for severe alopecia areata; trichoscopic monitoring of vellus regrowth tracks response.

Lectures covering this topic7 lectures

AAD 2026S041 · #01
Systemic Treatment of Androgenetic Alopecia: What's New
Jerry Shapiro, MD
AAD 2026S041 · #02
Lichen Planopilaris and Frontal Fibrosing Alopecia
Lidia Rudnicka, MD, PhD
Excellence (main)DE-MAIN · #10
Infectious Skin Diseases and Trichoscopy
G. Argenziano and A. Lallas
Excellence Intl 2025DE-INTL · #13
Inflammoscopy and Infectoscopy
Aimilios Lallas
Excellence PediatricDE-PED · #03
Inflammatory Disorders of the Skin in Children
Vincenzo Piccolo
ADM 2025ANNUAL13 · #11
Case-Based Learning: Context and Comparators
E. Vinny Seiverling, DO
ADM 2025ANNUAL13 · #28
Trichoscopy
David Swanson, MD

Notable updates & conceptual milestones7 updates

Low-dose oral minoxidil

2022-2026

Now standard treatment for AGA at 1.25-5 mg/day; tolerability and efficacy well established by 2024 trials.

JAK inhibitors for alopecia areata

2022-2024

Baricitinib (BRAVE-AA) and ritlecitinib (ALLEGRO) FDA-approved for severe AA; trichoscopic vellus regrowth predicts response.

Dutasteride mesotherapy

2023-2026

Intradermal dutasteride for AGA non-responders to oral therapy; emerging evidence of efficacy with low systemic exposure.

FFA pathogenesis insights

2022-2026

Sunscreen and personal-care-product associations strengthened; combined hydroxychloroquine + 5-alpha-reductase + intralesional steroid combination now widely used.

Trichoscopy AI

2024-2026

Hair-counting and miniaturization-tracking AI tools quantify treatment response objectively from serial images.

Oral vs topical minoxidil head-to-head RCT

2024

First head-to-head RCT showed daily oral minoxidil 5 mg was non-inferior to topical 5% twice daily for terminal hair density at 24 weeks; photographic scoring favored oral on the vertex with 49% hypertrichosis on oral.

Deuruxolitinib FDA approval (THRIVE-AA1)

2024

Deuruxolitinib FDA-approved July 2024 as the third oral JAK inhibitor for severe AA: 41.5% on 12 mg twice daily reached SALT 20 at 24 weeks vs 0.8% placebo.

Bottom line

Yellow dots, vellus, peripilar signs, the trichoscopic toolkit for AGA, alopecia areata, scarring alopecia and the LPP/FFA spectrum.

12 clinical points · 7 recent updates · 11 references

Source content

AAD 2026 · S041 · #01

Systemic Treatment of Androgenetic Alopecia

Jerry Shapiro, MD · NYU Grossman School of Medicine

AAD 2026 · S041 · #02

Lichen Planopilaris and Frontal Fibrosing Alopecia

Lidia Rudnicka, MD, PhD · Medical University of Warsaw

References

Sources cited in the lecture content or that underpin the clinical points above. Verify with primary sources before practice changes.

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