pasi_score: Psoriasis Area and Severity Index (PASI)

In cliot: Clinical Indices and Outcomes Tools

Psoriasis Area and Severity Index (PASI)

Description

Calculates the PASI score to assess the severity of psoriasis. The body is divided into four sections (Head, Arms, Trunk, Legs). Each section is scored for the severity of erythema, induration, and desquamation (0-4), and the percentage of area affected. The final score ranges from 0 to 72.

Usage

pasi_score(head_erythema, head_induration, head_desquamation, head_area_percent,
           arms_erythema, arms_induration, arms_desquamation, arms_area_percent,
           trunk_erythema, trunk_induration, trunk_desquamation, trunk_area_percent,
           legs_erythema, legs_induration, legs_desquamation, legs_area_percent)

Arguments

head_erythema	Numeric (0-4). Severity of redness on the head.
head_induration	Numeric (0-4). Severity of thickness on the head.
head_desquamation	Numeric (0-4). Severity of scaling on the head.
head_area_percent	Numeric (0-100). Percentage of head area affected.
arms_erythema	Numeric (0-4). Severity of redness on upper limbs.
arms_induration	Numeric (0-4). Severity of thickness on upper limbs.
arms_desquamation	Numeric (0-4). Severity of scaling on upper limbs.
arms_area_percent	Numeric (0-100). Percentage of upper limb area affected.
trunk_erythema	Numeric (0-4). Severity of redness on the trunk.
trunk_induration	Numeric (0-4). Severity of thickness on the trunk.
trunk_desquamation	Numeric (0-4). Severity of scaling on the trunk.
trunk_area_percent	Numeric (0-100). Percentage of trunk area affected.
legs_erythema	Numeric (0-4). Severity of redness on lower limbs.
legs_induration	Numeric (0-4). Severity of thickness on lower limbs.
legs_desquamation	Numeric (0-4). Severity of scaling on lower limbs.
legs_area_percent	Numeric (0-100). Percentage of lower limb area affected.

Details

Severity Scores: 0: None 1: Mild 2: Moderate 3: Severe 4: Very Severe

Area Scoring (Internal Conversion): 0%: 0 <10%: 1 10-29%: 2 30-49%: 3 50-69%: 4 70-89%: 5 90-100%: 6

Value

A list containing:

PASI_Score	The calculated total score.
Interpretation	General severity classification (Mild <=5, Moderate 5-10, Severe >10).
Subscores	Breakdown of weighted scores by body region.

References

Fredriksson T, Pettersson U. Severe psoriasis–oral therapy with a new retinoid. Dermatologica. 1978;157(4):238-244. doi:10.1159/000250825

Examples

# Example 1: Severe Psoriasis
# Head: 2,2,2, 50% | Arms: 3,3,3, 60% | Trunk: 2,2,2, 40% | Legs: 4,4,4, 80%
pasi_score(2,2,2,50, 3,3,3,60, 2,2,2,40, 4,4,4,80)

# Example 2: Mild Psoriasis
# Head: 1,0,1, 5% | Arms: 1,1,0, 5% | Trunk: 0,0,0, 0% | Legs: 1,1,1, 10%
pasi_score(1,0,1,5, 1,1,0,5, 0,0,0,0, 1,1,1,10)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.