Disease severity scoring systems in mucosal lichen planus: A systematic review

Several scoring systems have been developed to evaluate disease severity in mucosal lichen planus, but only a few have been validated to ensure reproducible and accurate assessment of disease severity. The current systematic review was undertaken to identify clinical severity scoring systems in mucosal lichen planus that have undergone validity or reliability testing and to describe their operating characteristics. We performed a bibliographic search in five databases from their inception to October 2022 for severity scoring systems in mucosal lichen planus that have undergone validity or reliability tests. Quality assessment was conducted using the Joanna Briggs Institute Critical Appraisal tools. We have included 118 studies and identified 11 clinical severity scoring systems for oral lichen planus that have undergone validity or reliability testing. Of these, the most reported were the Thongprasom score, the Oral Disease Severity Score (ODSS) and the REU (Reticular/hyperkeratotic, Erosive/erythematous, Ulcerative) scoring systems. We did not identify clinical scoring systems for extraoral mucosal lichen planus that have undergone validity or reliability testing. The ODSS and REU scoring systems have undergone the highest number of validation attempts and reliability assessments for oral lichen planus respectively. However, we have identified numerous factors that have hampered the universal adoption of a standardised scoring system. There is a need for the development and validation of scoring systems for extraoral mucosal lichen planus.