Botulinum Toxin for the Treatment of Intractable Raynaud Phenomenon
Practice Points
- Raynaud phenomenon (RP) is a vascular disorder characterized by episodic vasospasms of the digits often due to cold temperature or stress.
- OnabotulinumtoxinA has been implemented as a treatment of intractable RP after failure with traditional treatments, such as calcium channel blockers, angiotensin receptor blockers, prostaglandins, endothelin receptor blockers, and phosphodiesterase 5 inhibitors.
- A standard technique of delivery of onabotulinumtoxinA involves injection of 5 U/mL into the medial and lateral aspects of each finger at its base (near the metacarpal head) for a total of 50 U per hand or foot.
Studies have reported onabotulinumtoxinA to be a promising option for the treatment of intractable symptoms. Likewise, our patient had a notable reduction in pain with signs of clinical improvement within 24 to 48 hours after injection. The need for amputation 6 months later likely was because the patient’s toes were already necrosing prior to treatment with onabotulinumtoxinA. Thus, the timing of intervention may play a critical role in response to onabotulinumtoxinA injections, particularly because the severity of our patient’s presentation was comparable to other cases reported in the literature. Even in reports using a smaller dose—2 U injected into each toe as opposed to 10 U per toe, as in our case—follow-up showed favorable results.10 In other reports, response can be perceived within days to a week, with remarkable improvement of numbness, pain, digit color, and wound resolution, in addition to decreased frequency and severity of attacks. Moreover, greater vasodilation and subsequent tissue perfusion have been evidenced by objective measures including digital transcutaneous oxygen saturation and Doppler sonography.7,8 Side effects, which are minimal and temporary, include local pain triggering a vasospastic attack and intrinsic muscle weakness; more rarely, dysesthesia and thenar eminence atrophy have been reported.11
Available studies have shown onabotulinumtoxinA to produce favorable results in the treatment of vasospastic disease. We suspect that an earlier intervention for our patient—before necrosis of the toes developed—would have led to a more positive outcome, consistent with other reports. Treatment with onabotulinumtoxinA is an approach to consider when the standard-of-care treatments for RP have been exhausted, as timely intervention may prevent the need for surgery. The indications and appropriate dosing protocol remain to be defined, in addition to more thorough evaluation of its efficacy relative to other medical and surgical options.
