Efficacy of Botulinum Toxin In Scleroderma-Associated Raynaud's Syndrome

This is a randomized, double-blinded, clinical trial assessing the therapeutic efficacy of
Botulinum toxin A (Onabotulinumtoxin A) in treating scleroderma-associated Raynaud's
syndrome. Each patient will undergo injection with a treatment dose of Botulinum toxin A in
one randomly-selected hand, and the contralateral hand will be injected with sterile saline
(placebo) to serve as a control.

Study participants at the first study visit will complete study questionnaires, their hands
will be assessed clinically for digital ulceration, and their hands will undergo
non-invasive laser Doppler imaging to assess blood flow. After this initial assessment, the
patients will undergo peri-arterial injection of Botulinum toxin A in one hand, and of
sterile saline solution (placebo) in the other, in a randomized, blinded manner.

Patient will report the severity of their Raynaud's symptoms weekly over the four month
study period. At one month post-injection, the patient will complete study questionnaires,
their hands will be assessed clinically for digital ulceration, and their hands will undergo
non-invasive laser Doppler imaging. At four months post-injection, the patient will again
complete study questionnaires, their hands will be assessed clinically for digital
ulceration, and their hands will undergo non-invasive laser Doppler imaging. In addition,
patient will be given the option of one week post-injection visit, at which point the same
assessment will be performed.

At the conclusion of the study, unblinding will occur.