A mother-in-law and a daughter-in-law suffered chronic low back pain and they were injected epidural steroid on same day. Eleven days after injection, the daughter-in-law showed weakness of right lower extremity and lost filling sensation of bladder. Radiologic findings of Magnetic Resonance Imaging for lumbar spine revealed epidural abscess encompassing from L1 to sacral spine. After emergency surgical procedure and antibiotics therapy, the symptoms and the signs disappeared. Seven days after injection, the mother-in- law was diagnosed as pyogenic arthritis of right knee joint and then epidural abscess. Although the surgical procedure for right knee joint and antibiotics therapy were done, the epidural abscess didn't disappear. Moreover, surgical procedure for the epidural abscess couldn't be done due to septic condition, which was the cause of death. We report two cases of epidural abscess showing the importance of early management and serious end result. Prevention of these complication through extreme caution is needed. (J Korean Acad Rehab Med 2003; 27: 455-458)
