A complicated infection post-pelvic floor botulinum neurotoxin type A injection for chronic myofascial pelvic pain: A case report

Introduction: Botulinum neurotoxin A (BoNT-A) injections are increasingly used treatment for refractory myofascial pelvic pain. We report a complicated post-BoNT-A injection infection. Case description: A 27-year-old female patient with chronic myofascial pelvic pain presented for pelvic floor BoNT-A injection done in the operating room. Her past medical history was significant for ankylosing spondylitis being treated with Humira, daily smoking, and increased BMI. She presented to clinic 11 days later with progressively worsening left buttocks pain. On examination, she had a palpable indurated area with erythema on the left lower buttocks. She was admitted to hospital for pain management and IV antibiotics, initially Cefazolin and Metronidazole. CT scan showed an ischioanal collection. Antibiotic therapy was changed to Piperacillin/Tazobactam and Vancomycin. A percutaneous drain was placed on post-admission day 3 under ultrasound guidance which was removed 2 days later. An area concerning for necrosis was noted at the site of induration. The patient was taken to the OR for surgical debridement on post-admission day 7. She was discharged home on post-admission day 10 after transition to oral Amoxicillin/Clavulanate, which were continued for a total of 2 weeks. She was followed by the wound care team until resolution. Conclusion: BoNT-A injections are mostly performed on an outpatient basis in our clinical practice. Patients who undergo this procedure in the operating room are complexed and have risk factors predisposing them to infectious complication. They may require antibiotic prophylaxis.