VASI Calculator

Vitiligo Area Scoring Index — Hamzavi et al., 2004 · F-VASI as used in the TRuE-V trials (Rosmarin et al., 2022)

Purpose
Quantifies the extent of vitiligo as a composite of affected area (hand units) and degree of residual depigmentation per body region. Sensitive to repigmentation, so it is the standard outcome in vitiligo trials.
Population
Non-segmental (and segmental) vitiligo in adults and children. One hand unit = the patient's palm plus volar surface of all five digits ≈ 1% BSA.
Formula
VASI = Σall body sites [hand units] × [residual depigmentation]. Total VASI (T-VASI) 0–100; facial VASI (F-VASI) 0–3.
Severity thresholds
No validated severity bands. VASI is interpreted as change from baseline: VASI50 / VASI75 / VASI90 (≥ 50 / 75 / 90 % improvement); F-VASI75 is the usual primary end-point in trials.
🗺️ Scope

Six mutually exclusive regions: hands · upper extremities (excluding hands, including axillae) · trunk (including genitalia) · lower extremities (excluding feet, including buttocks) · feet · head/neck. Range 0–100.

🖐️ Area and residual depigmentation

For each region, estimate the total area of vitiligo in hand units (patient's own hand = palm + volar digits ≈ 1 % BSA) and the degree of residual depigmentation within those patches.

Residual depigmentation: 100 % no pigment present · 90 % specks of pigment · 75 % depigmented area exceeds pigmented · 50 % depigmented and pigmented equal · 25 % pigmented area exceeds depigmented · 10 % only specks of depigmentation.
📈 Interpreting change — reference

VASI has no severity bands. Record a baseline score and compare at follow-up:

  • VASI50 / VASI75 / VASI90 — ≥ 50 / 75 / 90 % reduction from baseline T-VASI.
  • F-VASI75 — ≥ 75 % reduction from baseline facial VASI: primary end-point of the ruxolitinib cream phase 3 trials (TRuE-V1/V2); F-VASI90 approximates cosmetically relevant facial repigmentation.
  • Score the same regions with the same patient hand unit at every visit; photographs (including UV/Wood's light) improve reproducibility.
📚 References
  1. Hamzavi I, Jain H, McLean D, Shapiro J, Zeng H, Lui H. Parametric modeling of narrowband UV-B phototherapy for vitiligo using a novel quantitative tool: the Vitiligo Area Scoring Index. Arch Dermatol. 2004;140(6):677–83.
  2. Rosmarin D, Passeron T, Pandya AG, et al. Two phase 3, randomized, controlled trials of ruxolitinib cream for vitiligo. N Engl J Med. 2022;387(16):1445–55.
  3. Pandya AG, Harris JE, Lebwohl M, et al. Addressing the unmet need in vitiligo: a review of measures used in TRuE-V phase 3 studies of ruxolitinib cream (supplementary material: F-VASI/T-VASI definitions). Dermatol Ther (Heidelb). 2024;14:2149–67.
  4. Rosmarin D, Pandya AG, Lebwohl M, et al. Ruxolitinib cream for treatment of vitiligo: a randomised, controlled, phase 2 trial. Lancet. 2020;396(10244):110–20.
  5. Seneschal J, Speeckaert R, Taïeb A, et al. Worldwide expert recommendations for the diagnosis and management of vitiligo: position statement from the International Vitiligo Task Force. J Eur Acad Dermatol Venereol. 2023;37(11):2173–84.
Clinical decision support only. This tool is intended to assist clinical assessment and does not replace professional judgment. Always interpret results in the context of the individual patient.