Serum Zinc Level and Efficacy of Zinc Therapy in Cutaneous Leishmaniasis: a Systematic Review and Meta-analysis

Cutaneous leishmaniasis is a parasitic skin disease prevalent in many parts of the world. Zinc has been investigated for its potential role in the immune response against Leishmania parasites. This study aimed to systematically review the literature and conduct meta-analyses to evaluate the serum zinc level and efficacy of zinc therapy in cutaneous leishmaniasis. A comprehensive search of electronic databases was performed to find studies reporting serum zinc levels and the efficacy of zinc therapy in cutaneous leishmaniasis. Meta-analyses were conducted using RevMan software (version 5.4), calculating the mean difference for serum zinc levels and risk ratio for the efficacy of zinc therapy. A total of 11 studies with 1009 participants were evaluated. Five of these studies, comprising 637 participants, examined serum zinc levels; the remaining six, involving 372 individuals, examined the effectiveness of zinc therapy in treating cutaneous leishmaniasis. The results showed that the serum zinc level was significantly lower in cutaneous leishmaniasis patients compared to controls (MD: - 26.65; 95% CI: [- 42.74, - 10.57]; p = 0.001). However, zinc therapy did not demonstrate a significant clinical improvement compared to standard treatment (RR: 0.96; 95% CI: [0.74, 1.23], p = 0.73).