The Psoriasis Area and Severity Index (PASI) is widely used to evaluate psoriatic disease activity in clinical settings; however, its limitations hinder its practicality in routine use. The Simple-Measure for Assessing Psoriasis Severity (S-MAPA) has emerged as a promising tool addressing these limitations, providing a more feasible approach for assessing disease severity. This study aimed to evaluate the S-MAPA as a sensitive and practical alternative to existing instruments for measuring psoriasis severity. Patients with psoriasis were assessed using body surface area (BSA), the Physician's Global Assessment (PGA), S-MAPA, PASI, and Dermatology Life Quality Index (DLQI). Plasma high-sensitivity C-reactive protein (hs-CRP) levels were also measured. Spearman's correlation analysis compared the relationships between these assessment tools and hs-CRP levels. In total, 100 assessments were conducted between January and July 2019. The S-MAPA score and PASI showed a strong positive correlation with disease severity (r=0.9315, p<0.01). Both the S-MAPA score and PASI exhibited comparable correlations with hs-CRP levels (r=0.5299 vs. 0.5316) and the DLQI (r=0.2533 vs. 0.2641). The S-MAPA score demonstrated stronger correlations with the PASI, DLQI, and hs-CRP level than with BSA or the PGA score. The area under the receiver operating characteristic curve for the S-MAPA was 0.9787, with an optimal cut-off value of 138 for predicting severe psoriasis (sensitivity, 92.59%; specificity, 95.89%). Based on our findings, the S-MAPA is a reliable and practical alternative for assessing the severity of psoriasis in clinical practice, offering advantages over conventional measures.
