A New Scale for Assessing the Severity of Uncomplicated Diaper Dermatitis in Infants: Development and Validation

Background One methodologic challenge in conducting research relating to diaper dermatitis (DD) is the absence of a reliable, objective, validated scale for assessing severity. The aim of this study was to develop and validate such a scale. Methods Scale development was based on experience of DD assessment and clinical and photographic data collected during the early stages of a randomized controlled trial of two DD treatments. The severity score is the sum of scores of four domains: severity of erythema and irritation, area with any DD, papules or pustules, and open skin. Possible scores range from 0 (clear skin) to 6 (extensive DD including intense erythema, papules or pustules, and open skin with damage to the dermis). Assessors used the scale to attribute severity scores using high‐definition photographs of infants and babies with DD. Interrater reliability (IRR), internal consistency, and test–retest reliability were considered using intraclass correlation coefficients (ICCs), Cronbach's α, and Cohen κ statistics. Results IRR was very good between assessors familiar with the scale (ICC = 0.949, p < 0.001) and between assessors unfamiliar with the scale (ICC = 0.850, p < 0.001). Test–retest reliability at 2 weeks was good (κ = 0.603, p < 0.001). Cronbach's α for internal consistency was 0.702. Collation of photographs according to severity score revealed a visible continuum of DD severity, suggesting good construct validity. Conclusion The newly developed scale appears to be easy to use, reliable, and effective in detecting increasing or lessening DD severity.