Syndrome of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) in siblings

PFAPA syndrome is characterized by episodes of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis. PFAPA syndrome usually begins in children under 5 years old and normally has self-resolution. The etiology of PFAPA syndrome remains unknown. In this paper, we report the cases of two different families with siblings with PFAPA syndrome: two sisters and two brothers. To our knowledge, this is the first report of siblings with PFAPA syndrome.