Performance of recently proposed periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome criteria in a region endemic for familial Mediterranean fever

The periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is an auto-inflammatory condition characterized by recurrent episodes of fever accompanied by aphthosis, cervical adenitis, and pharyngitis. Diagnosis of PFAPA could be challenging due to clinic overlap with familial Mediterranean fever (FMF). An international consensus has been established recently, to define a new set of classification criteria for PFAPA syndrome. We aimed to evaluate the performance of recently proposed PFAPA criteria, to assess their utility in FMF regions. Patients diagnosed with PFAPA syndrome, FMF, and juvenile idiopathic arthritis (JIA) were included. Two investigators blindly evaluated all of patients for the newly proposed PFAPA criteria. A total of 542 patients (322 with PFAPA syndrome, 118 FMF and 102 JIA) were evaluated. Mean age of patients was 6.6 +/- 2.81, 12.75 +/- 3.9, and 12.42 +/- 4.8 years for PFAPA, FMF, and JIA, respectively. We found quite high sensitivity (89.7%) but insufficient specificity of newly proposed PFAPA criteria (69.5%). When applied to control patients separately, specificity was found to be 61% and 79.4% for FMF and JIA patients, respectively. Positive predictive value was 81%, while negative predictive value was 82%. Recently proposed PFAPA criteria have satisfactory sensitivity, but its specificity is still under expectation. There is a need for a distinctive criterion between PFAPA syndrome and FMF, in FMF endemic regions, e.g., cryptic tonsillitis rapidly responsive to single dose of glucocorticoids. Further studies with higher patients' number in different regions are needed