Two siblings with periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome.

PFAPA syndrome (periodic fever, aphthous stomatitis, pharyngitis, adenitis) is a benign sporadic syndrome of unknown cause. We report 2 siblings diagnosed with this syndrome. The second case started crisis simultaneously with recurrence of crisis after a 3-year free interval in her brother. This temporal relation suggests environmental factor acting in genetically predisposed children.