Unusual complication of intravenous Subutex abuse: two cases of septic sacroiliitis.

We report two unusual cases of septic sacroiliitis resulting from intravenous Subutex abuse that initially masqueraded as low back pain. Both patients, a 48-year-old Malay man and a 30-year-old Malay woman, presented with chills, rigor and progressive lower back pain, and eventually experienced difficulty in ambulating. The Malay woman also developed severe pain in her left elbow, with swelling and restriction of movement. Blood investigations and cultures revealed an infective process. Imaging of the pelvis and lower back confirmed the diagnosis of septic arthritis of the sacroiliac joints. The first patient underwent computed tomography-guided drainage of the abscess and was administered intravenous antibiotics via a peripherally-inserted central catheter (PICC) line. The second patient underwent an arthrotomy for her elbow and her left sacroiliac joint was managed conservatively with intravenous antibiotics, also via a PICC line. The diagnostic difficulty and the need for a high index of suspicion are discussed.