DermDermatology
Psoriasis Area and Severity Index
Quantifies psoriasis severity and area. Score 0-72. PASI 75/90 are endpoints for biologic trials.
Head — Erythema (0–4)
Head — Induration (0–4)
Head — Desquamation (0–4)
Head — Area (0–6)
Upper Limbs — Erythema (0–4)
Upper Limbs — Induration (0–4)
Upper Limbs — Desquamation (0–4)
Upper Limbs — Area (0–6)
Trunk — Erythema (0–4)
Trunk — Induration (0–4)
Trunk — Desquamation (0–4)
Trunk — Area (0–6)
Lower Limbs — Erythema (0–4)
Lower Limbs — Induration (0–4)
Lower Limbs — Desquamation (0–4)
Lower Limbs — Area (0–6)
Reference: Fredriksson & Pettersson, Dermatologica 1978
Medical Disclaimer: This calculator is a clinical decision support tool for qualified healthcare professionals. It does not replace clinical judgement. Always interpret results in the full clinical context. Reference: Fredriksson & Pettersson, Dermatologica 1978.