Chronic Recurrent Multifocal Osteomyelitis in Crohn Disease

Abstract

A 16-year-old boy with recent weight loss and elevated inflammatory markers presented to the emergency department with abdominal pain. CT abdomen revealed ileal perforation, fluid collection in the right lower quadrant, and multiple areas of small and large bowel inflammation, suspicious for Crohn disease. He was treated with IV antibiotics and gut rest. During antibiotic therapy, he developed bone lesions in the vertebra most consistent with chronic recurrent multifocal osteomyelitis (CRMO) (Fig. 1). After he underwent surgical drainage for persistent fluid collection, Crohn disease was confirmed with endoscopy and biopsies; anti-tumor necrosis factor α therapy was initiated. He clinically improved with weight gain and normalization of inflammatory markers. A year later, repeat imaging showed complete resolution of the bone lesions (Fig. 2).FIGURE 1: MRI T1-weighted, postcontrast with fat saturation dated November 7, 2014. Multiple enhancing areas of bone marrow are present (right sacrum, L1, T12 shown by arrows). Other similar lesions were present on other images. MRI = ??.FIGURE 2: MRI T1 weighted, postcontrast with fat saturation dated October 1, 2015. The previously identified multiple enhancing areas of bone marrow have all completely resolved. MRI = ??.CRMO (now referred as chronic noninfectious osteomyelitis) has been described in literature as a rare extraintestinal manifestation of IBD (1,2). It is an aseptic inflammation of the metaphyses of long bones, although any part of the skeleton may be affected. It is considered autoimmune in etiology and has been described in association with other autoimmune diseases (3,4). When it occurs in association with IBD, often the bone lesions predate the gut symptoms (1). The lesions are always sterile and respond to anti-inflammatory therapy (2,6,7). UNCITED REFERENCE (5)