A Case of Rectus Sheath Hematoma Caused by Self-Injection of Certolizumab Pegol

Rectus sheath hematoma (RSH) is a condition caused by hemorrhage into the rectus sheath. A 61-year-old man with end-stage renal failure and rheumatoid arthritis presented to our hospital with abdominal pain. The patient had been receiving biweekly self-injections of certolizumab pegol to the abdominal wall. Computed tomography (CT) demonstrated a large high-density left-sided RSH. Abdominal pain gradually exacerbated; thus, transcatheter arterial embolization (TAE) for the left inferior epigastric artery (IEA) was performed. This is the first reported case of RSH caused by certolizumab pegol. Factors contributing to RSH include low abdominal wall fat, the use of auto-injector-based preparations, and anticoagulant use in dialysis.