Toxic megacolon in children with inflammatory bowel disease: clinical and radiographic characteristics.

BACKGROUND: Toxic megacolon (TMC) denotes a rare clinical syndrome accompanied by colonic dilatation, and is a serious complication of inflammatory bowel disease (IBD). This study assessed the clinical and radiologic characteristics of TMC in children with IBD.

METHODS: A systematic search identified patients with IBD-associated TMC and matched them by age to controls with ulcerative colitis without evidence of TMC. Clinical characteristics and outcomes were compared with conditional logistic regression. Abdominal X-rays were interpreted by two blinded radiologists and findings were compared with controls.

RESULTS: Ten children with TMC (median age 12.6 [7.3-15.5] yr) were matched with 20 controls (median age 12.8 [6.8-15.2] yr). Altered level of consciousness and hypotension were rare in children with TMC. Fever (P= 0.005), tachycardia (P= 0.0001), dehydration (P= 0.01), and electrolyte abnormalities (P= 0.0002) were more common in children with TMC than controls. Air-fluid levels (P= 0.005), intestinal thickening (P= 0.006), and abnormal colonic haustra (P= 0.012) were more commonly seen on X-rays of TMC cases. Transverse colon luminal diameter >or=56 mm was strongly suggestive of TMC (sensitivity 90%, specificity 90%, area under the ROC curve 0.91). No child with TMC died and 70% required colectomy during admission. Two of the three with intact colons at discharge required second-line therapy during the subsequent year.

CONCLUSIONS: Colonic dilatation >or=56 mm in children with IBD strongly suggests TMC, if clinical signs are present. Mental alteration and hypotension may be less common in children than in adults. TMC in children with IBD is associated with poor outcome, with a high rate of corticosteroid failure.