Background: PFAPA is an auto inflammatory syndrome with an unknown etiology. Recent findings suggest the possible role of the NLRP-3 inflammasome, similar to the mechanism in FMF. Israel is a melting pot and thus provides a unique opportunity to compare the prevalence and severity of this syndrome amongst different ethnicities in the presence of similar environmental factors.
Methods: Medical records of PFAPA patients from the Schneider Children`s Medical Center`s autoinflammatory clinic were reviewed for the period January 2014 – May 2016. Patients diagnosed with FMF were excluded. Discrete variables were compared using Pearson’s Chi-squared test or Fisher’s exact test. Continuous variables were compared between groups using ANOVA.
Results: Of the 91 patients studied, 58 (64%) were of Mediterranean, 28 (30.5%) mixed and 5 (5.5%) Ashkenazy ancestry (compared to ~ 40%, 30% and 22% respectively in the general population). 11% had a family history of a PFAPA or PFAPA-like disease and 29% had a family history of FMF. Patients of Mediterranean and mixed ancestries had a significantly higher flare frequency (Mediterranean 3.6 ± 2.4; Mixed 3.6 ± 1.4; Ashkenazi 6.8 ± 6.4 weeks; P=0.025). 28% of patients presented with a flare frequency of ≤ 2 weeks. An increase in flare frequency was experienced in 43% of all patients following recurrent treatment with a single dose of glucocorticoids.
Conclusion: About two-thirds of our PFAPA patients were of Mediterranean ancestry and only 5% were of Ashkenazy ancestry. Mediterranean and mixed ancestry patients presented with a more severe disease occurring at shorter intervals. 10% had a family history; more importantly, about one-third of the Mediterranean group had a history of FMF raising the possibility of a possible relationship between these 2 autoinflammatory syndromes in this population.
