Laser and light therapy combined with topical minoxidil for alopecia areata: a systematic review and meta-analysis of randomized controlled trials

Abstract

We aim to evaluate the clinical efficacy and safety of using laser and light combined with topical minoxidil for alopecia areata. We searched PubMed, Embase, Web of Science, the Cochrane Library, China National Knowledge Infrastructure (CNKI), China Biomedical Literature Database (CBM), VIP database, and Wanfang Data from their inception to September 18, 2022. The risk of bias of the included RCTs was assessed by the Cochrane Collaboration tool. RevMan 5.3 software and Stata 14.0 software were used to perform the statistical analysis. The GRADE system assessed the quality of evidence. Ten studies were enrolled finally. The results of the meta-analysis showed that compared with topical minoxidil alone, the 308-nm excimer laser/light or He-Ne laser combined with topical minoxidil could reduce the SALT (Severity of Alopecia Tool) score (MD= -5.88, 95% CI [-9.79, -1.98], P=0.003). Whether fractional CO₂ laser (RR=1.29, 95% CI [1.14, 1.46], P<0.0001), 308-nm excimer laser/light (RR=1.32, 95% CI [1.12, 1.55], P=0.001), He-Ne laser (RR=1.69, 95% CI [1.07, 2.69], P=0.03), or NB-UVB (RR=1.35, 95% CI [1.07,1.70], P=0.01) combined with topical minoxidil may improve the treatment response rate, comparing with topical minoxidil only. The recurrence rate of laser and light combined with topical minoxidil was lower than that of the minoxidil alone group (RR=0.54, 95% CI [0.31, 0.93], P=0.03) when follow-up time was 1 year. In addition, the incidence of adverse events including irritant contact dermatitis, erythema, desquamation, pain, and pruritus was no significant difference between the two groups (RR=1.50, 95% CI [0.95, 2.36], P=0.08). The level of evidence for outcomes was classified as very low to moderate. Based on the available evidence, laser and light combined with topical minoxidil therapy may be effective and safe for alopecia areata. However, more high-quality trials are required for comprehensive analysis and further verification.

Keywords: Alopecia areata; Laser; Light therapy; Meta-analysis; Minoxidil; Systematic review.