The Impact of Steroid Use on Scabies Treatment: An Evaluation of Clinical Severity, Parasite Burden, and the Validity of a Novel Scoring System

BACKGROUND: Corticosteroids are frequently used to relieve pruritus or eczematization in scabies, but empirical or prolonged use before diagnosis may modify the disease course. OBJECTIVES: This study aimed to examine the impact of corticosteroid exposure (misdiagnosis-related or adjunctive) on clinical severity, mite burden, and healing time, and to assess the initial measurement properties of a novel composite scoring system for standardized severity assessment. METHODS: In this cross-sectional analytical study, 180 adults (18-50 years) with dermoscopically confirmed scabies were classified into three groups: misdiagnosed (steroid-only), standard therapy + steroid, and standard therapy. Severity was assessed using a 0-9 composite score integrating pruritus (NRS), mite index, and body surface area involvement (BSA). Internal consistency (Cronbach's α) and inter-rater reliability (ICC) were evaluated. RESULTS: Both steroid-exposed groups showed significantly higher severity scores (all p < 0.001), longer disease duration (median 8 weeks vs. 3 weeks), and delayed healing compared with standard therapy. Steroid duration correlated with mite index, BSA, and total score (all p ≤ 0.005). The scale showed borderline-to-acceptable internal consistency; ICC was good for NRS (0.79) and fair-to-moderate for the total score (0.45). CONCLUSION: Prior or concurrent corticosteroid exposure increases disease severity and delays recovery in scabies, likely by suppressing local immune responses. The proposed Scabies Severity Scale is a practical, preliminary tool for standardized severity assessment, pending external validation.