Key Takeaways
- Wood’s lamp makes vitiligo borders chalk/blue-white with high contrast; confetti-like micro-macules at the rim suggest activity.
- Dermoscopy shows absent pigment network and perifollicular brown halos/dots signaling early repigmentation islands.
- Use a standard photo protocol and track change with F-/T-VASI and VIDA (activity) to guide therapy.
Wood’s Lamp: Setup & Diagnostic Criteria
- Room: darken fully; allow 3–5 min dark adaptation.
- Device: 365 nm UV-A, hold 5–10 cm from skin; examine borders first.
- Positive criteria:
- Bright chalk/blue-white accentuation vs surrounding skin.
- Sharp border enhancement; trichrome transitions possible.
- Confetti micro-macules at the rim → active disease.
- Negative/alternative clues: yellow-gold/coppery fluorescence (think tinea versicolor), low-contrast off-white (nevus depigmentosus, PIH).
Dermoscopy: Activity & Repigmentation Cues
| Sign | Meaning | Notes |
|---|---|---|
| Absent pigment network | Diagnostic support for depigmentation | Uniform in established plaques |
| Perifollicular brown halos/dots | Early repigmentation islands | Favorable prognostic sign (face/neck) |
| Starburst/confetti at border | Activity | Aligns with positive VIDA |
| White superficial scale | Differential (tinea/pityriasis alba) | Scrape accentuates scale |
Standardized Photo Protocol
- Consent & identifiers: site map, body diagram, date/time; mask sensitive data in EMR exports.
- Lighting: diffuse, same room, same lamps; avoid mixed color temperatures.
- Camera: 35–50 mm equivalent; manual mode if possible; keep ISO low; white balance fixed.
- Distances/angles: full-body, regional, and close-up at fixed marks on floor; include ruler/scale card.
- Wood’s lamp photos: turn off ambient light; lock exposure; take rim close-ups.
- Labeling: site, view, and session number; store in structured folders to enable automated comparisons.
Scoring & Documentation
- F-/T-VASI: estimate fractional depigmentation by anatomic region; record baseline and at 8–12 week intervals.
- VIDA score: capture activity (new/enlarging lesions, Koebner, confetti).
- Report template: diagnosis confidence (Wood’s/dermoscopy), activity status, high-risk sites (face/hands), and plan for combination therapy if indicated.
Pitfalls & Differential Hints
- Scale present? Think tinea/pityriasis alba; do KOH or emollient trial.
- Long-standing solitary patch since childhood? Consider nevus depigmentosus (stable, serrated borders).
- Exposure pattern with confetti macules? Consider chemical leukoderma; remove trigger.
- See Differential Diagnosis for a full table.