THE NEW ZEALAND MEDICAL JOURNAL Vol 116 No 1183 ISSN 1175 8716 NZMJ 10 October 2003, Vol 116 No 1183 Page 1 of 2 URL: http://www.nzma.org.nz/journal/116-1183/631/ © NZMA Delayed diagnosis of steroid-induced colon diverticulum perforation Andreas Kouyialis, Damianos Sakas, Efstathios Boviatsis, Nick Maratheftis and Stefanos Korfias Steroids are nowadays administered for the treatment of a variety of pathological conditions. Their beneficial effect is well established, but is quite often obviated by side effects, which can affect all systems. One of the lesser known but most life- threatening gastrointestinal side effects of steroids is the perforation of colonic diverticula, which may occur in about 2.7% of patients and carries a mortality risk of 27–100%. 1 Although this complication is more common after prolonged administration it may occur even after short treatment courses. This was first recognized by Beck et al in 1950, 2 but remains under-reported and the pathophysiological mechanism is poorly understood. Case report A 76-year-old woman was admitted to our department with paraparesis and significant muscle power loss of the upper extremities, present for four months. Magnetic resonance imaging of the cervical region revealed cervical spondylosis and cervical intervertebral disk herniation. She was started on oral methylprednizolone 32 mg/d along with ranitidine 300 mg/d. On the tenth day of corticosteroid therapy, she complained of abdominal discomfort. Physical examination revealed no signs of abdominal irritation or tenderness. Temperature, white blood cell count, C-reactive protein and serum biochemistry studies were normal. The patient’s clinical condition remained unchanged but four days later she complained of a sudden worsening of symptoms. The abdominal pain became diffuse and intolerable. She developed distention and rebound tenderness most marked in the left lower quadrant. A paracentesis of the abdomen revealed purulent and faecal fluid. Exploratory laparotomy revealed a left lower quadrant abdominal abscess, due to a perforated transverse colon diverticulum and a diffuse peritoneal inflammatory reaction. A segment of approximately 7 cm of the transverse colon was resected and was followed by an end-to-end anastomosis. The patient required prolonged treatment in the intensive care unit. She survived with a mild paraparesis. Discussion Colonic diverticula, being sites of stasis and prolonged exposure to high concentrations of colonic flora, are predisposed to bacterial invasion. Areas of mucosa in contact with the faecal stream undergo repetitive trauma. 3 Steroids inhibit the formation of ground substance and fibroblasts and cause alterations in structural protein synthesis, thus decreasing mucosal repair and renewal. 4 This enables intraluminal bacteria to penetrate the mucosa of the intestinal wall. Alteration of structural protein synthesis, thinning of the intestinal wall due to depletion of