summary Chronic Recurrent Multifocal Osteomyelitis (CRMO) is a condition characterized by idiopathic inflammatory disease of the skeleton that is associated with multiple sites of apparent osteomyelitis with negative cultures and no response to antibiotics. Diagnosis is one of exclusion and can be suspected with multiple eccentric metaphyseal lesions with sclerosis and new bone formation, with negative culture and pathology results. Treatment is usually symptomatic treatment with NSAIDS and pamidronate. Epidemiology Incidence incidence 1 in 250,000 prevalence 1 in 160,000 Demographics age primarily occurs in children/adolescents peak age of onset is 10 years old male: female ratio girls more common than boys Location the tubular long bones and clavicle are most frequently affected Etiology Pathophysiology poorly understood Criteria multiple sites of apparent osteomyelitis pathology and cultures are negative no response to antibiotics Associated conditions Pustulosis palmoplantaris syndrome a rare chronic relapsing condition causing red patches and pustules on the soles of the feet and palms of the hands considered a rheumatologic condition and no infectious agents have been identified following the outbreak of the lesions, desquamation occurs several days later associated with CRMO SAPHO Syndrome CRMO associated with: synovitis, acne, pustulosis, hypersotosis, osteitis Presentation Symptoms episodic fever malaise localized pain, swelling Physical exam focal tenderness in region of involvement Imaging Plain radiography findings eccentric lytic metaphyseal lesions with surrounding sclerosis and new bone formation Bone scan indications Can help determine other sites of disease MRI indications If concerned for malignancy, MRI can help determine presence or absence of soft tissue involvement Studies Laboratory values WBC typically normal ESR and CRP may be elevated Biopsy biopsy and bone cultures negative important to establish diagnosis which is one of exclusion Treatment Nonoperative symptomatic treatment with NSAIDS and pamidronate indications treat during exacerbations medications NSAIDs corticosteroids pamidronate can provide symptomatic improvement and stimulate vertebral remodeling Complications Growth disturbance rare but may occur Prognosis Natural history characterized by periods of remission and exacerbation typically resolves in 3-5 years Prognosis traditionally thought as having a relatively benign sequelae several case reports of growth disturbance have been reported.