Cluster Analysis in the Differential Diagnosis of PFAPA Syndrome.

This article focuses on differentiating Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis (PFAPA) syndrome from recurrent upper respiratory tract infections (URTIs) and familial Mediterranean fever (FMF) using demographic, clinical, and laboratory data. Through cluster analysis of 566 patients diagnosed with PFAPA, FMF, or URTI, the study identified distinct groups characterized primarily by each condition. Key variables distinguishing PFAPA included recurrent fevers beginning before age 5, presence of aphthous stomatitis, cervical lymphadenitis, pharyngitis, asymptomatic intervals between attacks, metallic taste during episodes, and elevated C-reactive protein and serum amyloid A levels. These findings aim to enhance diagnostic accuracy and support the development of standardized criteria for differentiating PFAPA from clinically similar disorders.