Criteria for the diagnosis of familial Mediterranean fever

Objective. To establish a new set of criteria for the diagnosis of familial Mediterranean fever (FMF). Methods. Twenty-seven features and manifestations typical of FMF were studied to determine their prevalence in 105 patients with FMF and 106 controls. Diagnosis of FMF in the study group was based on clinical judgment. Controls were patients with a variety of other diseases who presented to the emergency room or outpatient clinics with recurrent episodes of pain in body sites usually involved in FMF attacks. Manifestations observed to be significantly more common in FMF patients than in controls were incorporated into the rule proposed for diagnosis of FMF, based on a model of major, minor, and supportive criteria. Results. Two sets of diagnostic criteria were established. A conservative criteria set for diagnosis of FMF was based on the presence of 1 major or 2 minor criteria, or 1 minor plus 5 supportive criteria, and a simple criteria set for diagnosis of FMF required 1 major or 2 minor criteria. The sensitivity and specificity of these 2 criteria sets were >95% and >97%, respectively. Conclusion. The proposed new sets of criteria were highly sensitive and specific, and could be used to readily diagnose FMF and to distinguish FMF from other periodic febrile diseases.