Gastrointestinal involvement in a patient with familial Mediterranean fever mimicking Crohn's disease: a case report

Familial Mediterranean fever (FMF) in gastrointestinal involvement has been considered rare, but resent reports suggest that FMF causes enterocolitis which is similar endoscopic findings to inflammatory bowel disease. The clinical characteristics and endoscopic findings of FMF with enterocolitis remain unclear. Here, we report a case of an FMF patient who had enterocolitis with stricture of the terminal ileum whose endoscopic and clinical features mimicked Crohn's disease. A 23-year-old man who was diagnosed with FMF 10 years ago presented with abdominal pain and diarrhea. Colonoscopy showed terminal ileitis and aphthous colitis; however, these findings, including the histopathology, did not confirm Crohn's disease. Therefore, we diagnosed FMF with enterocolitis and administered anti-interleukin-1 beta monoclonal antibody (canakinumab). The patient's symptoms improved with treatment, but after 1 year, lower abdominal pain recurred. Colonoscopy revealed a stricture of the terminal ileum. Endoscopic balloon dilation relieved his symptoms. At present, he has been followed up without surgical treatment by endoscopic balloon dilation every 6 month. Clinicians should be aware that FMF accompanied with enterocolitis may resemble Crohn's disease.