Methods: The urticaria activity score (UAS) and urticaria-specific quality of life index (CU-Q2oL) were assessed at initial and follow-up visits for 17 adult patients with CU. Initial 25-hydroxy vitamin D levels were checked and repleted according to current guidelines. ANA and anti-IgE receptor antibody levels were measured at baseline and follow-up time points.
Results: Eight subjects were vitamin D deficient, 6 were insufficient, and 3 were sufficient. Initial and follow-up mean UAS were 3.67 to 0.75, 3 to 1.75, and 2.5 to 1.5 for the deficient, insufficient, and sufficient groups respectively. Initial and follow-up mean CU-Q2oL scores were 43.67 to 2.67, 35 to 10.25, and 42 to 51.5 for the deficient, insufficient, and sufficient groups respectively. IgE receptor antibody was positive in 4/7 deficient subjects, 2/6 insufficient subjects, and in no sufficient subjects. 1:160 ANA titers were in 3/7 deficient subjects, in no insufficient subjects, and in no sufficient subjects.
Conclusions: Vitamin D deficient and insufficient CU subjects demonstrated greater evidence of autoimmunity and follow-up improvement of CU symptoms with vitamin D repletion. The relationship between Vitamin D deficiency and CU may be mediated through an autoimmune mechanism. A larger study to confirm the observed trends is underway to examine these preliminary findings.