WORKING GROUP NAME: CHRONIC NONBACTERIAL OSTEOMYELITIS

Chronic nonbacterial osteomyelitis (CNO) is a severe, occult autoinflammatory bone disease of unknown cause. CNO commonly presents with bone pain, normal or mildly elevated inflammatory markers, x ray findings of lytic and/or sclerotic lesions and hyperintensity signal within bone marrow on MRI. The first line treatment of CNO is nonsteroidal anti-inflammatory drugs (NSAIDs). However, >40% of these patients fail NSAIDs and need additional treatments such as methotrexate, TNF alpha inhibitor, and pamidronate. Different criteria have been reported to define clinical responses to treatments in CNO. Most of these criteria included three main components: pain due to CNO, inflammatory markers (ESR and CRP), and imaging findings. However, a core domain set (CDS) recommendation for CNO has never specifically been made through standardized OMERACT methodology. We aim to develop a CDS for CNO that fulfills the requirements of OMERACT 2.0 Filter.