Psoriasis Area and Severity Index Use in Pediatric Psoriasis

Psoriasis Area and Severity Index (PASI) score is the primary instrument used to assess psoriasis severity and determine eligibility for clinical trials. The PASI scoring system assumes fixed adult body surface area (BSA) proportions for the head (10%), upper extremities (20%), trunk (30%), and lower extremities (40%); however, these proportions differ in pediatric populations. We conducted a systematic review of articles in Embase, PubMed, and Scopus, identifying more than 300 records. After quality appraisal using the Literature Review Scoring Rubric and manual relevance screening, 5 high-quality studies were included in our review. None addressed modification of PASI to account for age-related differences in BSA distribution. Because PASI scoring is used to determine pediatric clinical trial eligibility, reliance on adult BSA proportions may result in overinclusion or underinclusion of children. Based on these findings, we propose a modified PASI incorporating pediatric BSA estimates derived from the Parkland formula to improve accuracy in children and adolescents.