Rheumatoid Arthritis Induced by Botulinum Toxin Type A: A Case Report and Review of the Literature

Abstract

Introduction: Botulinum Toxin Type A (BoNT/A) is a bacterial toxin commonly used in cosmetic therapy. Although there has been a great deal of clinical and basic research on the potential therapeutic applications of botulinum toxin there are few reports on its clinical toxicity and side effects. Patient Concerns: A previously healthy 26-year-old woman developed joint pain and redness in her right toe, swelling in the posterior left foot and the interphalangeal joint of the right index finger, occasional shoulder pain, and morning stiffness for 30 minutes daily, 6 months after BoNT/A injection. Diagnosis: Laboratory testing showed elevated Rheumatoid Factor (RF), anti-cyclic citrullinated peptide (anti-CCP), C-Reactive Protein (CRP), Erythrocyte Sedimentation Rate (ESR). Doppler ultrasound examination of the right hand and both feet showed synovial hyperplasia of the right wrist, right second proximal interphalangeal joint, both ankles, and right first metatarsophalangeal joint, as well as bony erosion in a left intertarsal joint. Magnetic Resonance (MR) examination for right hand showed multiple joint changes of right hand and wrist, which included synovium thickening and enhancement. She was diagnosed as rheumatoid arthritis. Interventions: BoNT/A injection was stopped. Methotrexate 10mg was given once weekly and hydroxychloroquine 0.2g was given twice daily with subsequent remission of arthritis. Outcomes: At 12 months from diagnosis, patient reported complete joints remission. Conclusions: This is the first report of rheumatoid arthritis caused by botulinum toxin injection, and we speculate on the mechanism of its occurrence in this paper. In addition, we systematically introduce the latest research results on the development mechanism of BoNT/A causing RA. This review suggests that it is necessary to further explore the specific mechanism of RA or osteochondral injury caused by BoNT/A, which will not only help to improve the current understanding of the potential toxic and side effects of BoNT/A in clinical application, but also promote the standardization of clinical application of BoNT/A.