PASI (Psoriasis Area and Severity Index)

Grades overall plaque-psoriasis severity by combining lesion appearance (redness, thickness, scaling) with affected body-surface area across four regions, giving a composite score and band to track response to treatment over time.

Head & neck — Erythema (redness)

Head & neck — Induration (thickness)

Head & neck — Desquamation (scaling)

Head & neck — Area involved

Upper limbs — Erythema (redness)

Upper limbs — Induration (thickness)

Upper limbs — Desquamation (scaling)

Upper limbs — Area involved

Trunk — Erythema (redness)

Trunk — Induration (thickness)

Trunk — Desquamation (scaling)

Trunk — Area involved

Lower limbs — Erythema (redness)

Lower limbs — Induration (thickness)

Lower limbs — Desquamation (scaling)

Lower limbs — Area involved