Botulinum toxin type A in the treatment of Raynaud's phenomenon: A three-year follow-up study.

Botulinum toxin is a useful treatment for severe Raynaud's phenomenon that is generally well tolerated. Its mechanism of action is not based exclusively on vasodilation. Further studies are necessary to define the ideal patient for this treatment, the most appropriate method of administration, and the number of units and frequency of the infiltrations.