Tolerability and efficacy of botulinum toxin injection in the treatment of bromhidrosis: a systematic review and meta-analysis of clinical trials.

This review evaluates the risks and benefits of botulinum toxin (BTX) therapy for treating bromhidrosis. A search was conducted across six databases, including clinical trials comparing BTX therapy with BTX-free controls. The analyzed outcomes included pooled adverse events (AEs), treatment success, ≥ 50% overall improvement, and recurrence rates. Subgroup and sensitivity analyses were performed. Fourteen trials involving 1,293 participants were eligible. The BTX group experienced significantly fewer AEs than controls (relative risk [RR], 95% confidence interval [CI]: 0.33 [0.20-0.54]). Subgroup analysis indicated that the AE reduction was significant only when compared to small skin incision procedures. Overall, BTX did not show significant treatment success (RR [95% CI]: 1.06 [0.85-1.34]) or ≥ 50% improvement (RR [95% CI]: 0.98 [0.93-1.03]). However, BTX demonstrated superior treatment success compared to electrocauterization (RR [95% CI]: 1.45 [1.15-1.83]) and ethanol injection (RR [95% CI]: 2.27 [1.49-3.45]). Against placebos, BTX significantly reduced odor intensity (mean difference [95% CI]: 1.39 [-2.63 to -0.16]). Nevertheless, the recurrence rate was significantly higher in the BTX group (RR [95% CI]: 3.80 [1.06-13.67]). Notably, most studies (n = 9) were of low quality. In conclusion, although BTX is safe, it is not effective for the treatment of bromhidrosis.