Tonsillar microbiota in children with PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and adenitis) syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) is a childhood febrile syndrome of unknown origin that is often cured with tonsillectomy. We aimed to compare the bacterial microbiota of the tonsils removed from PFAPA patients with those of controls. We used next-generation sequencing technology to investigate the bacterial microbiota of the tonsils of 30 PFAPA patients and 24 controls. We found significant differences in the presence and relative abundance of many bacteria between PFAPA cases and controls. For example, cyanobacteria, potential producers of microcystins and other toxins, were more common in the case samples (14/30, 47 %) than in the controls (4/24, 17 %, p = 0.02), and the mean relative abundance of cyanobacteria was higher in the case samples (0.2 %) than in the controls (0.01 %, p = 0.01). Streptococci were present in all samples in both groups, but their mean relative abundance was lower in the case samples (3.7 %) than in the controls (9.6 %, p = 0.01). Typical nasopharyngeal microbes such as fusobacteria, Prevotella, Tannerella, Porphyromonas, and Parvimonas dominated the microbiota of the tonsils in both groups. The microbiota of the tonsils removed from PFAPA patients differed significantly from those of the controls. Tonsillar microbiota may play a role in triggering the inflammatory processes that lead to symptoms of PFAPA.