The Association between Vitiligo and Infections: A Systematic Review.

Vitiligo is an acquired depigmentation disease with an unknown etiology. Several theories on its etiology have been proposed, including autoimmune mechanisms, oxidative stress, genetic factors, environmental factors, and lack of melanocyte growth factor. Recent studies have demonstrated a possible correlation between microbial infections and the development or consequences of vitiligo. This study aims to investigate the potential association between microbial infections and vitiligo, focusing on identifying any explainable correlations between these two. A systematic search was performed on all publications evaluating the effects of viral, bacterial, parasitic, and fungal infections on vitiligo using online databases such as PubMed, Scopus, and Web of Science from 2010 up to June 2023 and followed the preferred reporting items for systematic review and meta-analysis (PRISMA) checklist. Viral infections, such as human immunodeficiency virus, varicella-zoster, and hepatitis C, are suggested triggers of vitiligo, potentially through immune dysregulation, cytokine imbalances, the Koebner phenomenon, and altered cellular immunity. Activation of MDA5 and vitamin D deficiency have also been proposed as mechanisms for virus-induced vitiligo. Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can dysregulate CD8+ lymphocytes and activate proinflammatory cytokines, disrupting immune tolerance and triggering or exacerbating vitiligo. Additionally, bystander activation triggered by coronavirus may cause an immune response against the host's melanocytes. Other factors such as Helicobacter pylori infection, endophytic bacterial and fungal infections, and vitamin D deficiency may also contribute to vitiligo pathogenesis by altering cellular immunity and systemic inflammation. Overall, a better understanding of the multiple factors that contribute to vitiligo may help inform more effective treatments and management strategies for this challenging condition.