If you are participating in a psoriasis clinical trial, you will hear the term PASI frequently. Understanding what it measures can help you track your own progress during the study.
What Is the PASI Score?
PASI stands for Psoriasis Area and Severity Index. It is the most widely used measure of psoriasis severity in clinical research and regulatory submissions. The PASI score ranges from 0 (no psoriasis) to 72 (maximum disease severity).
How Is PASI Calculated?
A trained investigator evaluates four body regions separately: head, trunk, upper extremities, and lower extremities. For each region, three things are scored:
- Erythema (redness), 0 to 4
- Induration (thickness), 0 to 4
- Desquamation (scaling), 0 to 4
The area affected in each region is also scored on a 0 to 6 scale. These scores are combined using a weighted formula.
What Is a High PASI Score?
- Mild: PASI below 10
- Moderate: PASI 10 to 20
- Severe: PASI above 20
Most clinical trials enroll participants with a PASI of 12 or above.
What Is PASI 75, PASI 90, and PASI 100?
These are common endpoints used in psoriasis trials:
- PASI 75: At least a 75% reduction in PASI score from baseline
- PASI 90: At least a 90% reduction, considered near-complete clearance
- PASI 100: Complete clearance of all psoriasis
Modern biologic therapies can achieve PASI 90 and even PASI 100 responses in many patients.
Interested in our psoriasis trial? Call NuLine at 754-331-5331.