Efficacy of botulinum toxin type A injection for Raynaud's phenomenon and digital ulcers in patients with systemic sclerosis

Introduction: Systemic sclerosis (SSc) is an autoimmune, connective tissue disorder of unknown etiology which causes vasculopathy and fibrosis. Raynaud's phenomenon (RP) is a common com-plication of SSc, which leads to ischemia and gangrenes. Treatment of RP is a clinical problem and often remains insufficient. This study aimed to evaluate the therapeutic efficacy of local injections of botulinum toxin type A (BTX-A) in improving the symptoms of Raynaud's phenomenon (RP) secondary to scleroderma.Material and methods: This parallel single-blinded, placebo-controlled clinical trial enrolled 29 pa-tients with scleroderma. Participants received BTX-A in the first, 2nd, 3rd, and 4th dorsal web spaces and the base of the thumb and small finger of the non-dominant hand and 2.5 ml of sterile normal saline in the opposite hand. Pre-injection measurements and post-injection follow-up evaluations at months 1 and 4 were performed. We compared the outcomes using the paired Student's t-test.Results: The change in pain severity between pre-injection and month 1 follow-up was significantly larger in the BTX-A group (p-value = 0.04). Between pre-injection and month 1 and month 4, the changes in the Raynaud's condition score (RCS) (p-value = 0.02, 0.004, respectively) and the number of Raynaud's attacks (p-value = 0.006, 0.001, respectively) were significantly greater in the BTX-A group. No significant difference was found in terms of paresthesia, skin thickening, upper extremity function, ulcer diameter, number of ulcers, or Raynaud's attack duration between the two groups (p-value > 0.05). In time, the decrease in pain severity, paresthesia, RCS, number of ulcers, and ulcer diameter, and the increase in upper extremity function were significantly greater in the BTX-A group as compared to the placebo group (p < 0.05).Conclusions: Our study showed that local injection of BTX-A is safe and has beneficial therapeutic effects on RP and RP-related digital ulcers in SSc patients.

Automated summary

This study evaluated the therapeutic efficacy of local injections of botulinum toxin type A (BTX-A) in improving the symptoms of Raynaud's phenomenon (RP) secondary to scleroderma. The results showed that BTX-A had a significant positive effect on pain severity, Raynaud's condition score, and the number of Raynaud's attacks. The improvements in pain severity, paresthesia, Raynaud's condition score, number of ulcers, ulcer diameter, and upper extremity function were significantly greater in the BTX-A group compared to the placebo group over time.