Challenges in the diagnosis of chronic immune-mediated rheumatic diseases

Diagnosing patients with immune-mediated rheumatic diseases has many facets to be considered, but early and rapid diagnosis is an important prerequisite for correct and straight-forward future management of the patients. For optimal results physicians should not miss any diagnosis (assuring high sensitivity of the diagnostic process), and high specificity is needed in view of future therapeutic interventions. This review focuses on select principal aspects of diagnosis in clinical practice: Challenges of diagnostic approaches in immune-mediated rheumatic diseases include the frequent lack of diagnostic criteria (with subsequent misuse of classification criteria), the urgent need for diagnostic values of history and further examinations to support diagnosis-finding strategies, and differential diagnoses to be excluded (e.g., infections during early disease and follow-up). First, pure application of classification criteria without expert's experience as diagnostic criteria may lead to inappropriate diagnoses in 4-32% of all patients with immune-mediated rheumatic diseases. Second, sensitivity and specificity data for history and clinical examination are necessary not only for routine clinical work, but also for purposes of teaching students and learning physicians. Third, conditions to be excluded before classification of a certain disease are not necessarily excluding a certain diagnosis. Specific interest is given to differentiate infections from early onset or relapse of immune-mediated rheumatic diseases.