BACKGROUND: Familial Mediterranean fever (FMF) is the most frequent monogenic autoinflammatory disorder; and leads to the uncontrolled production of interleukin (IL)-1β. Multiple sclerosis (MS) is an inflammatory disease of the central nervous system; and its development seems to be partly correlated with IL-1β levels. It is hypothesized that FMF could be associated with MS. We aim to describe the features of patients displaying both diseases and to investigate the MEFV mutation rate in MS patients.
METHODS: Patients with definite MS were retrieved from the cohort of FMF patients in the Reference Center for Rare Auto-inflammatory Diseases and Amyloidosis (CEREMAIA). We also performed a systematic literature review of articles from PubMed that were published from 1990 to 2020.
RESULTS: Twenty-four patients were included in the case series: five patients (1.3%) from our cohort of 364 and 19 patients from the literature. The sex ratio was 2:1. The mean age at diagnosis of FMF was 19 years old; and that for MS was 29 years old. Seven studies investigating the MEFV mutation rate in MS patients were included. Three studies found a higher mutation rate in MS patients than in the control group.
CONCLUSIONS: FMF and MS features were comparable to those of patients with unrelated diseases; and MEFV mutation carriage was not positively correlated with MS. However; MS prevalence in FMF patients was higher than was expected in a healthy population. To a lesser extent; FMF prevalence in MS patients was higher than expected in a healthy population and the difference might not be significant. These data suggest that FMF could be associated with MS; and further studies are needed to investigate a potential causal association.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most frequent non-hereditary autoinflammatory disorder in childhood: Its onset is usually observed before 5 years, though reports regarding adulthood are increasing. The pathogenesis of the syndrome is not completely understood, but a multifactorial origin, probably based on a polygenic pattern of susceptibility, is the most probable rational pathogenetic hypothesis. Treatment of PFAPA syndrome relies on the administration of low-dose corticosteroids, which promptly abort flares but cannot prevent subsequent disease episodes over time. Tonsillectomy with or without adenoidectomy has proved to be successful in some pediatric patients, as proven by different studies. On the other hand, colchicine, cimetidine, nonsteroidal anti-inflammatory drugs, and interleukin-1 inhibitors have shown efficacy, which require further definite confirmations. This review is aimed at summarizing all the recent evidence about treatment options available for PFAPA syndrome both in pediatric and adult patients.