Serum Levels of 25-hydroxyvitamin D in Chronic Urticaria and its Association with Disease Activity: A Case Control Study.

AIM: To evaluate the relationship between vitamin D levels and chronic spontaneous urticaria (CSU) and compare with healthy age and sex matched controls.

MATERIAL AND METHODS: This was a hospital-based cross-sectional study conducted over a period of 1 year, in which 110 patients with CSU were recruited along with an equal number of sex and age-matched healthy controls. For each patient, urticaria activity score (UAS) was calculated and autologous serum skin test (ASST) was performed. Plasma 25-hydroxyvitamin D [25-(OH)D] was analyzed by chemiluminescence method. A deficiency in vitamin D was defined as serum 25-(OH)D concentrations <30 ng/mL. The statistical analysis was carried out by using appropriate statistical tests.

RESULTS: The mean serum 25-(OH)D levels of CSU patients was 19.6 ± 6.9 ng/mL, whereas in control group, the mean level was 38.5 ± 6.7, the difference being statistically significant ( P < 0.001). A significant negative correlation was found between vitamin D levels and UAS. ( P < 0.001). The number of patients with ASST positivity was 44 (40%).

CONCLUSION: The patients with CSU had reduced levels of vitamin D when compared to healthy controls. Furthermore, there was a significant negative correlation between the levels of serum vitamin D and severity of CSU.