Development of the Mycetoma Activity and Severity clinical Scale (MASS): an international Delphi study

Mycetoma is a chronic, subcutaneous infection that causes local tissue destruction, leading to deformity, disability, and social stigma. Safe and effective treatments for mycetoma are urgently needed; however, there is no systematic measure that allows objective clinical assessment of disease severity and activity, which makes it difficult to accurately assess the effectiveness of treatments and draw comparisons between studies. A Delphi study was conducted, involving a panel of 23 mycetoma experts from five continents, to establish consensus on the structure, wording, and content of a clinical scoring system for mycetoma. Three rounds of anonymous surveys were conducted between August, 2023 and May, 2024. Consensus was defined as 65-85% agreement and strong consensus if 85% or higher. The final version of the Mycetoma Activity and Severity clinical Scale (MASS) consisted of 20 items, 14 pertaining to disease severity and six to disease activity, grouped into objective clinical features, patient-reported measures, and investigations. Consensus was achieved for 19 of the 20 items, and a strong consensus for 14. The MASS is the first clinical scoring system for mycetoma derived from a consensus approach and will facilitate accurate evaluation of treatment response if adopted into routine clinical practice by health-care workers across mycetoma-endemic regions. The MASS will also serve an important function as a research tool for use in prospective clinical studies and comparative drug trials.