Diagnostic approaches to Kawasaki disease worldwide: the results from the JIR-CliPS network

Objectives: To evaluate worldwide differences of diagnostic approaches to Kawasaki disease (KD), focusing on aspects, which vary throughout major international guidelines, including criteria for diagnostic and risk stratification. Methods: An online English-language survey was distributed to physicians worldwide between June 2022 and November 2024 through the JIR-CliPS (Juvenile Inflammatory Rheumatism; Clinical Practice Strategies) network, aiming to collect real-life diagnostic and management practices in juvenile rheumatic conditions, including KD. Responses addressing the definitions of complete and incomplete KD and criteria identifying patients at high-risk for coronary artery lesions (CALs), were analysed. Descriptive statistics, comparisons of categorical variables, sensitivity and weighted analysis were performed. Results: 192 physicians from 51 countries completed the survey. All respondents accepted ≥5 days of fever plus four criteria as diagnostic for complete KD. 32% (n = 62/192, 95%CI [25.74, 39.40]) also accepted shorter fever duration, particularly physicians from France (n = 16/24, 63%, 95%CI [44.68, 84.37]). 94% (n = 178/189, 95%CI [89.83, 97.06]) diagnosed incomplete KD based on fever and three clinical criteria. 44% (n = 84/189, 95%CI [37.23, 51.83]) accepted the presence of CALs as diagnostic in febrile patients, even without other clinical criteria; this approach was more common among Europeans. Infant age and elevated coronary Z scores were identified as key indicators for coronary involvement. Years of experience did not influence the results. Conclusion: Despite shared core diagnostic principles, country-specific differences persist in real-life clinical practice regarding fever duration, minimum clinical criteria, and the role of coronary artery findings in diagnosing complete and incomplete KD. Future real-life studies are needed to support timely and consistent diagnosis.