Key Takeaways
- Wood’s lamp hallmark: sharply demarcated bright chalk/blue-white accentuation of macules/patches.
- Activity signs: confetti depigmentation, trichrome borders, and Koebner streaks → ongoing spread.
- Repigmentation sign: dermoscopic perifollicular brown dots/halos = early islands (favorable response).
- Photos matter: standardized angles, distance, and exposure enable trustworthy F-/T-VASI tracking and surgical stability checks.
Wood’s Lamp Criteria
- Classic vitiligo: bright chalk/blue-white fluorescence with sharp borders that extend beyond what is visible in ambient light.
- Trichrome: central depigmentation → hypopigmented rim → normal skin; often indicates activity.
- Confetti: clusters of 1–3 mm bright flecks at edges → high activity; defer surgery.
- Leukotrichia: bright white hair within a patch; predicts slower cutaneous fill-in but useful surgical target if stable.
- Technique: dark room 3–5 min adaptation; hold lamp 5–10 cm from skin; shield ambient light; examine borders first.
Dermoscopy: Activity vs Repigmentation
| Pattern | Meaning | Implication |
|---|---|---|
| Perifollicular brown dots/halos | Early repigmentation islands | Continue regimen; consider taper/maintenance soon |
| Confetti flecks | Active melanocyte loss | Escalate therapy; maintenance later |
| Linear “scrape” streaks | Koebnerization (friction) | Friction control + optimize regimen |
| Uniform pale network | Post-inflammatory hypopigmentation (PIH) more likely | Reassurance; emollients/anti-inflammatory care |
Distinguishing from Look-Alikes
- Tinea versicolor: yellow/coppery glow; fine scale → consider KOH; see differential.
- Pityriasis alba: low-contrast off-white; dry cheeks in children.
- Nevus depigmentosus: since childhood; serrated borders; stable segment.
- Lichen sclerosus/morphea: ivory plaques, atrophy/induration → biopsy if doubt.
- Chemical leukoderma: exposure-mapped splatter pattern; remove trigger.
Standardized Photo Protocol
- Setup: neutral background, standing posture, fixed marks on floor; camera 1.5–2.0 m (body) / 40–60 cm (face/hands).
- Camera: same device each visit; disable auto-filters/HDR; manual exposure if possible; flash off for Wood’s lamp series.
- Angles: frontal + 45° oblique + lateral per site; include one scale reference (ruler/known object).
- Wood’s series: lights off; lamp 5–10 cm; 2–3 frames per border; capture rims where activity suspected.
- File naming:
YYYYMMDD_site_view_light(e.g.,20251112_face_frontal_woods). - Consistency: replicate distance/angles each visit; avoid cosmetics the day of photography.