[Periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome]

Periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome is a non-hereditary autoinflammatory disease, characterized by relatively regular recurrence of febrile episodes of 3-6 days duration, accompanied by aphthous stomatitis, pharyngitis/tonsillitis, and/or cervical adenititis. It is considered to be the most common periodic fever syndrome in Japan. Although no responsible gene is identified, some genetic factors may confer the predisposition toward this disorder. Important differential diagnosis includes hereditary periodic syndromes and cyclic neutropenia. Although its etiology is still to be elucidated, a recent study suggested an environmentally triggered activation of complement and IL-1β/IL-18 during PFAPA syndrome flares, with induction of Th1-chemokines and subsequent retention of activated T cells in peripheral tissues. This study also demonstrated the possibility that IP-10/CXCL10 might serve as a potential biomarker to differentiate PFAPA syndrome from other periodic fever syndromes. Therapeutic strategy for PFAPA syndrome has not been well established. Recent advances in the understating of etiology and pathophysiology might lead to re-evaluation of recent therapeutic options and/or development of new treatment.