Clinical features and new diagnostic criteria for the syndrome of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis.

The syndrome of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) is a common inflammatory disease that presents with periodic fever. We aimed to establish more specific diagnostic criteria for PFAPA based on the clinical characteristics of PFAPA patients in our directory.The clinical, laboratory, genetic, and family history details of 257 Japanese PFAPA patients treated at our and other affiliated hospitals between April 2000 and April 2018 were analyzed along with quantitative measurements of the number of CD64 molecules on neutrophils, and the levels of serum inflammatory cytokines. The sensitivity and specificity of the criteria were calculated for several diseases.Because recurrent fevers were crucial findings, they were defined as the required criterion. Tonsillitis/pharyngitis with white moss were important accompanying signs. Other symptoms associated with febrile episodes were cervical lymphadenitis with tenderness, aphthous stomatitis, sore throat, vomiting, and headache but not cough. A total of 159 (62%) patients had a family history of recurrent fevers, indicating autosomal dominant inheritance. C-reactive protein levels were extremely elevated during febrile attacks but normal in attack-free periods. Serum immunoglobulin D levels were high in 72 of the 199 tested patients. Oral glucocorticoid and cimetidine were extremely effective in all and 51.6% of the patients, respectively. We defined the above as supportive criteria. These criteria were sensitive and specific enough to distinguish PFAPA from other recurrent fever diseases. Raised serum interferon-γ levels and remarkable CD64 expression on neutrophils during flare-ups were recognized, indicating they contributed to diagnosis.Our new criteria are useful for diagnosing PFAPA.