Chronic recurrent multifocal osteomyelitis (CRMO), also called chronic nonbacterial osteomyelitis (CNO), is an autoinflammatory bone disorder. This rare disease primarily affects children and adolescents. Children with CRMO may sometimes have other diseases as well, including inflammatory bowel disease (IBD) or certain genetic syndromes. Because many doctors are unfamiliar with CRMO, children are commonly misdiagnosed as having a bone infection (infectious osteomyelitis). Although CRMO can have symptoms that are similar to that of infectious osteomyelitis, children with this disease do not have a bacterial infection.
Symptoms vary among children but may include joint or bone pain, swelling or warmth. Any bone can be affected, but the long bones of the arms and legs, the collarbones, and the jaw bones are most common. Some children may experience fevers, rashes or gastrointestinal complaints.
CRMO is a diagnosis of exclusion, which means that other diseases that can cause bone inflammation (such as infections and malignancies) must be ruled out before the diagnosis can be made. There are no specific diagnostic tests or biomarkers for this disease, but blood tests can be helpful by ruling out other causes. Imaging, such as X-rays and MRIs, may also be helpful. If the diagnosis remains unclear, a bone biopsy may be necessary.
Treatment depends on the severity of symptoms and on whether and where any bony lesions are present. Typically, NSAIDs (nonsteroidal anti-inflammatory drugs), corticosteroids, immunosuppressive drugs or bisphosphonates can be used. In children with associated disorders (such as IBD), it is important to treat the underlying disease. Your doctor may order a whole-body MRI to monitor the child’s progress during treatment.
Reviewed and edited by Sarah Faith Taber, MD