CNO (CNO is the acronym for "chronic non-bacterial osteomyelitis") is an autoinflammatory, non-bacterial bone disease with a wide spectrum of clinical manifestations, ranging from unifocal to multifocal lesions.
Chronic recurrent multifocal osteomyelitis(CRMO) on the other hand, is a severe form of CNO, usually characterized by symmetric, inflammatory bone lesions, and their waxing and waning manifestations.