Is Botulinum Toxin an Efficacious Treatment for Raynaud Phenomenon?

Botulinum toxin therapy shows significant efficacy in treating Raynaud phenomenon, according to study results published in the Journal of Clinical Rheumatology.

Induced by cold or emotional stress, Raynaud phenomenon is associated with functional abnormalities, such as small vessel contraction, vascular wall fibrosis, and calcification. Treatments for Raynaud phenomenon include avoiding cold temperatures, use of vasodilators, and surgical interventions. As Raynaud phenomenon is induced by sympathetic vasoconstriction, botulinum toxin may have clinical applications in Raynaud phenomenon.

Researchers conducted a systematic review and meta-analysis to explore the safety and efficacy of botulinum toxin therapy for Raynaud phenomenon. For the analysis, researchers searched publication databases through August 2022 for relevant studies.

A total of 13 studies of retrospective (n=5), prospective (n=4), and randomized trial (n=4) designs were included in the analysis. The studies were conducted in the United States (n=4), Spain (n=2), the United Kingdom (n=2), Japan (n=2), Iran (n=2), and China (n=1) and were published between 2009 and 2022. Most studies used botulinum toxin A (n=11). The average follow-up durations ranged between 1 to 4 weeks and 3 years.

The pooled sample size comprised 286 patients, of whom 269 received botulinum toxin. The patients were diagnosed with primary or secondary Raynaud phenomenon, Raynaud phenomenon secondary to systemic sclerosis, or Raynaud phenomenon secondary to scleroderma.

Data from 125 patients indicated that botulinum toxin treatment decreased visual analog scale (VAS) pain scores (standardized mean difference [SMD], -3.82; 95% CI, -6.62 to -1.02 points). Similarly, data from 76 patients indicated the botulinum toxin associated with a significant reduction in Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score (SMD, -0.83; 95% CI, -1.47 to -0.19 points).

Study limitations include small sample sizes, a lack of control groups, and less than a year of follow-up among the selected studies for the meta-analysis.

“The results of this single-arm meta-analysis revealed that Btx [botulinum toxin] injections for the treatment of RP [Raynaud phenomenon] resulted in lower VAS pain and QuickDASH scores,” the study authors wrote. “However, the evidence might not be strong enough in light of the inconsistent patient population, injection techniques, and outcome parameters in published works. Future research with larger sample sizes and comparison groups is warranted.”

This article originally appeared on Rheumatology Advisor