The Use of Botulinum Toxin in Raynaud Phenomenon: A Comprehensive Literature Review.

[BACKGROUND] Raynaud phenomenon (RP) is a vasospastic condition of the digits that can be primary or secondary to systemic disease. Symptoms are triggered by cold or stress and can cause pain and skin color changes. The chronic ischemia may lead to necrosis, ulceration, and amputation. There are no Food and Drug Administration-approved treatments and cases refractory to pharmacologic and surgical treatments are difficult to control. Local botulinum toxin injections have been increasingly used in the treatment of Raynaud disease and have shown promising results.

[AIM OF THE STUDY] To examine the outcomes, techniques, and complications of botulinum toxin use for the treatment of Raynaud disease.

[METHODS] The PubMed database was queried using "botulinum toxin" AND "Raynaud phenomenon" as title key words. Preferred reporting items for systematic reviews and meta-analysis criteria were used. Additional articles were selected while reviewing the references of the articles from PubMed. No time restrictions were followed. Articles of all languages were included. Articles were analyzed for study type, demographics, diagnosis/inclusion criteria, treatment methods, outcome measures, length of follow-up, results, and complications. A positive outcome was defined as subjective improvement in symptoms and/or improvement in the outcome measures. A poor outcome was defined as harm done to the patient by the injection that would not have occurred otherwise.

[RESULTS] Forty-two clinical studies describing the use of botulinum toxin for Raynaud's phenomenon were found. A total of 425 patients with primary or secondary Raynaud's were treated, with ages ranging from 14 to 91 years. There were 342 women and 81 men, with a female-to-male ratio of 38:9. Outcomes were positive in 96.2% of patients. There were 14.2% of the studies that reported 3.5% of all patients showing no subjective improvement. A single study reported a poor outcome for 1 patient. There were 40.5% of the studies that reported complications, affecting 20.2% of all patients. The most frequently reported complication was transient hand weakness, affecting 44.2% of patients with complications and 8.9% of total patients. Weakness resolved in hours to months after injection. Pain at the injection site lasting minutes to days was reported in 40.7% of patients with complications, and 8.2% of total patients.

[CONCLUSIONS] Botulinum toxin treatment for RP is effective. Complications are minor and self-limiting.