Serum 25-Hydroxy Vitamin D Levels in Patients with Polymorphic Light Eruptions: A Case-control Study

Abstract

Introduction: Polymorphic Light Eruptions (PMLE) are immune mediated dermal maculopapular eruptions that occurs after sun exposure. Vitamin D deficiency has been gaining attention in many dermatological diseases of varied pathologies. Research studies on vitamin D levels in PMLE are lacking despite it being an immuno modulator. Aim: To estimate the levels of serum 25-OH Vitamin D among patients with PMLE disease and also to compare its level with healthy controls Materials and Methods: A case-control study was conducted during January 2022 to June 2022 in Melmaruvathur Adhiparasakthi Institute of Medical Sciences and Research Hospital, Tamil Nadu, India. Total 80 participants (40 patients with PMLE eruptions and 40 normal healthy volunteers), of both sexes aged between 40-60 years were included. Serum 25-OH Vitamin D levels were estimated for participants and the data obtained were analysed by using Student’s t-test and Chi-square test as tests for significance and Odds ratio by logistic regression as test for outcome association. Results: Amongst the total 80 participants, 40 in each case and control group, mean age in case group was 50.08±5.21 years and in control group was 49.80±5.68 years. The results of the study showed significantly reduced serum 25-OH vitamin D levels (30.13±7.39 ng/mL) among cases compared to controls (34.50±6.05 ng/mL) (p=0.005). It further showed significant positive B (0.160) slope for sunlight exposure and significant negative B (-0.556) slope for serum vitamin D levels with odds of occurrence to PMLE disease state increases by 17.4% for every unit increase in sunlight Ultraviolet (UV) exposure {Odds ratio: 1.174 (C.I: 1.088-1.266)} and decreases by 42.6% for every unit increase in Vitamin D levels {Odds ratio: 0.574 (C.I: 0.446-0.738)}. Conclusion: Most PMLE patients were found to have significantly lower Vitamin D levels with majority in the pre- deficient zones. These findings suggest Vitamin D could be a cost effective alternative prospect in both PMLE diagnostics and therapeutics in future after thorough trial validations.