Validation of PARACELSUS score performance for the diagnosis of pyoderma gangrenosum: An international multicenter study with 1403 cases

Moelleken M, Ortega-Loayza AG, Busch D, Erfurt-Berge C, Shinohara MM, Do A, Libertad Ortega Nuñez D, Vega MD, Dini V, Romanelli M, Karrer S, Kurz B, Gontijo JRV, Goerge T, Kaffenberger BH, Isoherranen K, Nobbe S, Nguyen L, Stücker M, Dissemond J (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Journal of the American Academy of Dermatology Elsevier

DOI: 10.1016/j.jaad.2026.02.101

Abstract

Background Pyoderma gangrenosum is a rare ulcerative neutrophilic dermatosis which is challenging to diagnose due to heterogeneous presentation and overlap with other ulcerative diseases. Currently, PARACELSUS score is the most sensitive diagnostic tool, but its specificity is limited. Objective Evaluation of PARACELSUS score for diagnosis of diverse wound etiologies. Methods International, multicenter, retrospective observational diagnostic accuracy validation study included 1403 cases from 14 institutions in 7 countries (2022-2024). All cases had a confirmed diagnosis of pyoderma gangrenosum or other wound entities. Diagnostic accuracy statistics were applied to PARACELSUS score using established and potential cut-off values. Results Among 1403 cases (57.0% women, 43.0% men; mean age 62 years), 85 wound entities were identified, including 180 cases of PG. Raising the diagnostic cut-off from ≥10 to >10 points improved specificity (93.2% vs 96.8%; P < .001), positive predictive value (68.4% vs 81.9%; P < .001) and accuracy (94.1% vs 97.0%; P < .001). The false-positive rate was decreased (6.8% vs 3.2%; P < .001) with a non-significant reduction in sensitivity (100.0% vs 98.3%; P = .25). Limitations Retrospective data collection and heterogeneity of participating centers may limit generalizability. Conclusion Adjusting PARACELSUS score cut-off to >10 points significantly improves specificity and accuracy while maintaining high sensitivity, thereby reducing false-positive diagnoses.

Authors with CRIS profile

Dorothee Busch Department of Dermatology Cornelia Erfurt-Berge Department of Dermatology

Involved external institutions

Universitätsklinikum Essen DE Germany (DE) Oregon Health and Science University (OSHU) US United States (USA) (US) University of Washington US United States (USA) (US) University of the Mexican Army and Air Force / Universidad Del Ejército Y Fuerza Aérea MX Mexico (MX) University of Pisa / Università di Pisa (UniPi) IT Italy (IT) Universitätsklinikum Regensburg DE Germany (DE) Universidade Federal de Minas Gerais (UFMG) BR Brazil (BR) Universitätsklinikum Münster DE Germany (DE) The Ohio State University Wexner Medical Center (OSUMC) US United States (USA) (US) Helsinki University Central Hospital (HUCH) / Helsingin seudun yliopistollinen keskussairaala (HYKS) FI Finland (FI) Kantonsspital Frauenfeld CH Switzerland (CH) Universitätsklinikum Hamburg-Eppendorf (UKE) DE Germany (DE) Katholisches Klinikum Bochum (St. Josef- und St. Elisabeth-Hospital gGmbH) DE Germany (DE)

How to cite

APA:

Moelleken, M., Ortega-Loayza, A.G., Busch, D., Erfurt-Berge, C., Shinohara, M.M., Do, A.,... Dissemond, J. (2026). Validation of PARACELSUS score performance for the diagnosis of pyoderma gangrenosum: An international multicenter study with 1403 cases. Journal of the American Academy of Dermatology. https://doi.org/10.1016/j.jaad.2026.02.101

MLA:

Moelleken, Maurice, et al. "Validation of PARACELSUS score performance for the diagnosis of pyoderma gangrenosum: An international multicenter study with 1403 cases." Journal of the American Academy of Dermatology (2026).

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