Evaluation of botulinum toxin A injections for the treatment of refractory chronic digital ulcers in patients with systemic sclerosis.

[OBJECTIVES] To evaluate the therapeutic benefit of botulinum toxin A (BTX-A) injections for digital ulcers (DU) in patients with systemic sclerosis (SSc).

[METHODS] A systematic literature review was performed and the identified articles were selected by two reviewers and analysed with respect to date of publication, inclusion and exclusion criteria, number and age of participants, volume of BTX-A, injection sites, outcomes, and adverse events. In addition, in the Zurich cohort, 7 SSc patients were eligible for the study and were assessed for the duration of DU to heal, duration of DU-free periods, changes in frequency and numbers of prescribed vasodilators, pain and blood flow.

[RESULTS] In five articles from the systematic review, at least 48% of DU had healed and up to 100% reduction in VAS for pain was reported. Our 7 patients (median age of 53 (47-82) years) had in median 2.5 (2-4) DU and were injected with a median BTX-A volume of 90 (50-100) units per hand. Of the 31 DU in all patients, 77% (n=24) healed. Time to wound closure was in median 8 (4-12) weeks and the DU-free duration was in median 8 (3-10) months. In 80% of the cases, at least one vasodilator was stopped or could be administered less frequently. An improvement of blood flow and pain was reported in 60% of the cases.

[CONCLUSIONS] BTX-A injections might be of benefit for the treatment of chronic, refractory DU in selected SSc patients, yet a sufficiently powered prospective study will be needed as ultimate proof.