Psoriasis Area and Severity Index Fredriksson Version Clinical Classification

**Semantic type:** Intellectual Product

**Definition:** A standardized index developed in 1978 by Fredriksson et al. that combines psoriasis disease severity (measured as erythema, infiltration, and desquamation) and body surface area involvement over 4 body regions (head, trunk, upper and lower extremities) to assess progress during treatment.

**Synonyms:** - PASI FREDRIKSSON - PASI Fredriksson Version - PASI03