MASI / mMASI (Melasma Area and Severity Index)

Quantifies melasma severity across four facial regions to track disease and treatment response; a research/clinical severity index, not a diagnosis, and mMASI (homogeneity dropped) is the modern validated standard now used in most trials.

Forehead (×0.3) — Area of involvement (A)

Forehead — Darkness (D)

Forehead — Homogeneity (H) — classic MASI only

Right malar (×0.3) — Area of involvement (A)

Right malar — Darkness (D)

Right malar — Homogeneity (H) — classic MASI only

Left malar (×0.3) — Area of involvement (A)

Left malar — Darkness (D)

Left malar — Homogeneity (H) — classic MASI only

Chin (×0.1) — Area of involvement (A)

Chin — Darkness (D)

Chin — Homogeneity (H) — classic MASI only