Association of Serum Zinc Levels with Melasma Severity: A Cross-Sectional Analytical Study

Background: Melasma is a common acquired disorder of facial hyperpigmentation with a chronic, recurrent course. Zinc is an essential trace element with antioxidant and anti-inflammatory functions and may influence melanocyte activity and the skin response to oxidative stress, but its relationship with clinical severity of melasma remains incompletely defined. Objective: To evaluate the association between serum zinc levels and the clinical severity and extent of melasma. Methods: This cross-sectional analytical study included 104 clinically diagnosed melasma patients, purposively recruited from the Department of Dermatology, Dhaka Medical College Hospital, from January to December 2025. Melasma type was classified by Wood’s lamp, and severity by the modified Melasma Area and Severity Index (mMASI). Serum zinc was measured in the hospital laboratory (deficiency: <70 µg/dL). Associations between zinc status and ordered severity categories were tested with the chi-square test for trend, and continuous variables with Pearson’s correlation (95% CI). Analysis used SPSS version 26; p<0.05 was considered significant. Results: Of the 104 participants, 90 (86.5%) were female and 53 (51.0%) were aged 30–39 years. Mixed melasma was the predominant type (61.5%), centrofacial involvement was most common (66.3%), and 61 (58.7%) had severe disease. Zinc deficiency was identified in 71 (68.3%). Serum zinc correlated negatively with disease duration (r=−0.481; 95% CI −0.62 to −0.32), mMASI area score (r=−0.843; 95% CI −0.89 to −0.78) and mMASI severity score (r=−0.787; 95% CI −0.85 to −0.70; all p<0.001). Zinc deficiency was significantly more frequent with increasing mMASI severity and facial involvement (both p<0.001). Conclusion: Lower serum zinc concentrations were associated with greater severity, more extensive facial involvement and longer duration of melasma. Because of the cross-sectional design and unadjusted analysis, these findings do not establish causality. Prospective and interventional studies are needed.