Chronic Non-Bacterial Osteitis/Chronic Recurrent Multifocal Osteomyelitis

Abstract

Chronic non-bacterial osteitis (CNO) is a rare disease, which is a great mimic of infectious osteomyelitis (Table 1). It is currently classified as an autoinflammatory osteopathy. Autoinflammatory diseases are a group of disorders characterized by seemingly unprovoked inflammation in the absence of high-titer antibodies or antigen-specific T-cells. CNO primarily affects children, although it can be seen in any age group (Girschick, Raab et al. 2005). It is a disease of unknown etiology that was first recognized 4 decades ago as a disorder of non-infectious bone inflammation. It was initially described as “subacute and chronic symmetrical osteomyelitis,” which affected multiple bones either simultaneously or sequentially with a recurrent pattern (Giedion, Holthusen et al. 1972). Later, similar noninfectious osteitis has been described as both multifocal and unifocal disorder, with recurrent or monophasic course, and in association with other inflammatory conditions such as ankylosing spodylitis, psoriasis, and inflammatory bowel disease. Recurrent episodes of painful swollen lesions of the bone are noted, elevated ESR can occur, and radiographic changes can be confused with bacterial osteomyelitis. Negative findings on culture are the rule, and no improvement is noted with antimicrobial therapy.