Vitamin D deficiency as a risk factor for PFAPA syndrome

Objective: The periodic fever, aphthous stomatitis, pharangytis and cervical adenitis (PFAPA) syndrome, is an idiopathic chronic disease of non-hereditary origin, primarily affecting pre-school children and is the most common periodic fever disorder in children. Rapid response to corticosteroid treatment suggest an immune dysregulation. Recently, emerging evidence suggest that vitamin D plays an important role in immunity regulation. The aim of our study was to assess the vitamin D levels in children with PFAPA syndrome. Methods: This study was conducted prospectively. We have consecutively evaluated 50 patients after having excluded other causes of recurrent fever between May 2017 and May 2018 in addition to age-matched 50 patients as control group. All patients has complete physical examination and laboratory tests. Laboratory tests included complete blood count, C-reactive protein (CRP), and vitamin D levels. Serum 25 (OH) vitamin D levels were measured in all patients twice yearly. Results: Vitamin D levels was 18 +/- 10 ng/ml in the patient group and 35 +/- 13 ng/ml in the control group. There was statistically significant difference between the groups (p < 0.001). 38 patients from the PFAPA group and 20 patients from the control group had low vitamin D levels. Multivariate logistic regression analysis showed that CRP (odd ratio (OR) = 2.7, 95% confidence interval (CI) = 2.4-4.1) and serum 25 (OH) vitamin D levels < 30 ng/ml OR = 2.1, 95% CI = 1.8-2.5) were associated with PFAPA occurrence. Conclusion: We found strong correlation between PFAPA and vitamin D insufficiency. Hypovitaminosis D can be a significant risk factor for PFAPA episode recurrence.