Association of Serum Vitamin D Concentration with the Severity of Patients with Atopic Dermatitis.

Abstract

Atopic Dermatitis (AD) is a chronically relapsing, highly pruritic, allergic inflammatory skin disease with significant cost and morbidity to the patients and their families. The underlying cause of AD has not been understood, however some studies have shown initial epidermal barrier defect with subsequent immune activation as the underlying mechanism of AD. Vitamin D is now recognized as an immunomodulator. The role played by vitamin D in atopic dermatitis is controversial and has been the focus of many studies. The aim of the study was to measure serum vitamin D in the form of 25-hydroxy vitamin D in patients with AD and to correlate them with disease severity. This cross-sectional study included 41 patients (25 males and 16 females) of any age with the clinical diagnosis of AD seen in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from September 2015 to February 2017. Disease severity was determined using Scoring Atopic Dermatitis (SCORAD) index and the patients were divided into three groups: mild (SCORAD index <25), moderate (25-50) and severe (>50). Serum vitamin D levels were classified as sufficient (≥30ng/mL), insufficient (21-29ng/mL) and deficient (≤20ng/mL). Statistical analysis was performed using analysis of variance (ANOVA) and Pearson's correlation coefficient test. P value of <0.05 was considered as statistically significant. Among 41 patients 33 represent infantile and childhood AD and only 8 represent adolescent and adult AD. According to SCORAD index, 12 patients had mild, 20 had moderate and 9 had severe Atopic dermatitis. Levels of 25-hydroxyvitamin D were deficient or insufficient in 75.6% of patients and normal in 24.4% patients. There was no significant association between serum level of vitamin D and the severity of AD (r=-0.173). The mean±SD serum vitamin D level in mild AD (25.7±8.1) was higher compared with those with moderate (23.9±8.8) or severe (19.5±8.3) AD. But the result was not statistically significant (p=0.249). Variables such as sex, age, skin prototype, season and food allergy were not significantly associated with vitamin D levels. The results from this study suggesting that millions of children living in Bangladesh may have suboptimal levels of vitamin D, which should be a matter of public health concern. But these deficient results are not significantly related to AD severity. Thus, the study provides epidemiological evidence against the association of vitamin D status with atopic dermatitis for the first time in Bangladesh.