Systemic sclerosis, also known as scleroderma, comprises a group of rare diseases that involve the hardening and tightening of the skin, and may also cause problems in the blood vessels, internal organs, and digestive tract. It’s estimated that about 300,000 Americans have scleroderma, and about one-third of those individuals have the systemic form of the autoimmune disease.

While there is no cure for the condition, the results from a new study suggest that botulinum toxin (BTX) injections is a safe and effective adjunctive treatment for refractory ischemic digital complications, including acute digital ischemia, digital ulcers, and gangrene. The study by Zhu et al is published in JAMA Dermatology.

Study Methodology

The researchers conducted a systematic review of MEDLINE (PubMed), Embase (Ovid), and Scopus databases and an individual participant data meta-analysis to evaluate the effectiveness and safety of BTX injections for ischemic digital complications and identify predictors of treatment response. The eligible studies included data from 119 patients who presented with acute digital ischemia, ischemic digital ulcers, or gangrene. The patients were mostly female (75%); and the mean age was 49 years.

The primary outcome of the study was complete response (CR), which was defined as resolution of ischemia or ulcer healing. Secondary outcomes included adverse events and time to response. Cox regression was used to identify factors associated with complete response.

Results

The researchers found that BTX was associated with high CR rates for ischemia (93.1%), ulcers (90.1%), and gangrene (87.5%). Adverse events were infrequent, with transient muscle weakness (7.6%), and injection site pain (5.9%) being most common. No associated factors reached statistical significance in multivariable models, but autoimmune etiology and younger age were associated with faster response in Kaplan-Meier analyses.

“The results of this systematic review and IPD meta-analysis suggest that BTX injections appear to be a safe and effective adjunct for refractory digital ischemia in systemic sclerosis. Prospective trials are needed to confirm long-term effectiveness and standardize administration protocols,” concluded the study authors.

Key Points

• BTX injections appear to be a safe and effective adjunctive treatment for refractory ischemic digital complications, including acute digital ischemia, digital ulcers, and gangrene.

• Prospective trials are needed to confirm long-term effectiveness and standardize administration protocols.