Chronic Non-bacterial Osteomyelitis: A Review

Area of Science:

• Pediatric rheumatology
• Auto-inflammatory diseases
• Bone disorders

Background:

• Chronic non-bacterial osteomyelitis (CNO) and its severe form, chronic recurrent multifocal osteomyelitis (CRMO), are rare auto-inflammatory bone disorders.
• While typically affecting children, CNO/CRMO can occur in all age groups and affect nearly any bone.
• Diagnosis is challenging, often requiring exclusion of bacterial osteomyelitis and malignancy.

Purpose of the Study:

• To review current knowledge on the epidemiology, pathophysiology, diagnosis, and treatment of CNO/CRMO.
• To identify areas for future research and propose refinements to diagnostic criteria.
• To consider unifocal jaw cases as a potential distinct subtype.

Main Methods:

• Literature review of existing studies on CNO/CRMO.
• Analysis of diagnostic modalities, particularly magnetic resonance imaging (MRI).
• Evaluation of current and emerging treatment strategies.

Main Results:

• CNO/CRMO is characterized by recurrent episodes and low-grade inflammation, with MRI being a key diagnostic tool.
• Treatment typically involves NSAIDs for symptom relief, but bisphosphonates and biologics are increasingly used to prevent bone damage.
• Unifocal jaw involvement may represent a distinct subtype requiring specific diagnostic criteria.

Conclusions:

• Further research is needed to clarify the pathophysiology and refine diagnostic criteria for CNO/CRMO.
• Early and aggressive treatment may be necessary to prevent long-term bone sequelae.
• Establishing distinct criteria for jaw-specific CNO/CRMO could improve patient management.