Crohn's Disease Presenting as an Abdominal Wall Abscess in an Adolescent With Autism Spectrum Disorder.

Crohn's disease (CD) is a subtype of inflammatory bowel disease characterized by discontinuous lesions and transmural inflammation. Delayed diagnosis may lead to fistula formation between the intestine and adjacent organs. However, most CD-associated fistulas are enteroenteric or perianal, and abdominal wall abscesses are rarely reported in pediatric patients. We report a case of CD presenting as an abdominal wall abscess in a 15-year-old girl with autism spectrum disorder. Contrast-enhanced computed tomography revealed a fistulous communication between the abscess cavity and the transverse colon. Percutaneous drainage and antibiotic therapy were performed to control the infection. Colonoscopy demonstrated skip lesions with longitudinal ulcers, cobblestone-like mucosa, and inflammatory polyps. Histopathological examination showed active chronic colitis compatible with inflammatory bowel disease. Remission induction therapy consisting of elemental diet, 5-aminosalicylic acid, and corticosteroids was initiated after infection control. Her clinical condition gradually improved, and she was discharged on hospital Day 37. During follow-up, her appetite improved and she gradually gained weight. At 18 months after discharge, contrast-enhanced computed tomography showed no recurrence of the abdominal wall fistula, and her clinical condition remained stable. In pediatric patients, CD may present with nonspecific systemic symptoms, which can delay diagnosis. In patients with autism spectrum disorder, communication difficulties may further obscure gastrointestinal symptoms. Clinicians should consider underlying inflammatory bowel disease when children present with unexplained abdominal wall abscesses accompanied by systemic symptoms such as growth failure or malnutrition.