Diagnosis and/or classification of vasculitis: different?

PURPOSE OF REVIEW: Currently, there are no diagnostic criteria for vasculitides. To this end, there is a current European League Against Rheumatism and American College of Rheumatology initiative for formulating separate classification and diagnostic criteria for different forms of vasculitis. The authors of this review previously disagreed to separate classification and diagnostic criteria. They now expand this disagreement in light of both of more recent information and a reassessment of older communications.

RECENT FINDINGS: We still can find no clear methodologies proposed to prepare separate diagnostic and classification criteria. Furthermore, the inadequate importance given to probabilities in discussing disease criteria was strikingly apparent. Among 77 articles on diagnostic/classification criteria making, not more than 4% discussed Bayes' theorem or predictive values or confidence intervals. The misconceptions related to the worry about circularity and the proper role of nomenclature in classification and diagnostic criteria continue.

SUMMARY: Separate diagnostic and classification criteria are unrealistic. Classification criteria and nomenclature are only tools to a proper diagnosis, essentially not different for patient care or research. A frank discussion of probabilities in diagnosis is essential not only with the patients but also with all the stakeholders.