The immunology of the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome; what can the tonsils reveal. A literature review.

Tonsillectomy (TE) or adenotonsillectomy (ATE) may have a beneficial effect on the clinical course in children with the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome. However, an immunological reason for this effect remains unknown. This literature review summarizes the current knowledge regarding the immunological role of the tonsils in the PFAPA syndrome.We searched PubMed, Medline, EMBASE and Cochrane for papers written in English dated from 1 January 1987 to 30 April 2019. The search included all studies reporting histological, immunological or microbiological workup of tonsil specimens from children aged 0-18 years with PFAPA.Thirteen articles reported histological, immunological or microbiological workup of tonsil specimens in children with PFAPA. The histology of tonsil specimens from children with PFAPA displayed chronic tonsillar inflammation with lymphoid hyperplasia. No uniform immunological pattern was identified, but some studies found fewer B-lymphocytes and smaller germinal centers in PFAPA compared to controls. A difference in tonsillar microbiota between PFAPA and controls was found in one study.A uniform immunological or microbiological pattern explaining the clinical effect of TE in children with PFAPA has not been revealed. Future targeted immunological studies of tonsils in PFAPA patients could possibly illuminate the understanding of the immunology in this disease.