Safety and efficacy of UV application for superficial infections in humans: A systematic review and meta-analysis.

Background: Ultraviolet (UV) light is naturally antimicrobial, but risks associated with UV overexposure have limited its clinical application. This systematic review evaluates the safety and efficacy of UV light treatment of superficial human infections.

Methods: MEDLINE, Embase, Cochrane CENTRAL, ANZCTR and US National Library of Medicine were searched (March 25, 2020). Clinical studies applying UV light (200-400 nm) for superficial infections and non-clinical studies evaluating the antimicrobial effects of UV light on human samples were included. Randomised controlled trials (RCTs) and non- RCTs were appraised using the Cochrane risk of bias and the ROBINS-I tools, respectively.

Results: Eleven RCTs, seven non-RCTs, 24 case studies, and 11 in vitro studies were included. Most clinical studies (34/42) evaluated UVA treatment for microbial keratitis (MK) using cross-linking (UVA-CXL) methods. Six clinical studies assessed UVC; one, UVB; and one, broadband UV for chronic skin infections. Pooled data analysis showed no difference in the time to wound resolution with UVA-CXL relative to standard treatment (mean difference [MD]: -18.20 [95% CI: -39.04 to 2.65] days; p = 0.09). Adverse event incidence was similar to control for UVA-CXL in MK (RR: 0.70 [95%CI: 0.32-1.79]; 5 RCTs) and UVC in skin infections (RR: 0.63 [95%CI: 0.25-1.54]; 2 RCTs).

Conclusion: Alone or as an adjunct to standard therapy, UV light shows promise as a safe and effective treatment for a wide range of infections. Applications of UV light as an anti-infective agent are deserving of further evaluation, especially in the context of growing antibiotic resistance.

Registration: PROSPERO registration number CRD42020176510.