Chronic recurrent multifocal osteomyelitis (
CRMO) is a sporadic condition of inflammatory bone
pain that occurs as recurrent flares because of
osteomyelitis, which presents in the form of multiple aseptic foci. The estimated prevalence of
CRMO is 1-2 per million, affecting mostly children, in the age group of 2 to 17. Main symptoms of
CRMO are
bone inflammation and
pain, which are generally worse at night. Other symptoms seen on radiographs indicate osteolytic lesions surrounded by
sclerosis, at later stages of the disease. Markers of
inflammation, viz.
tumor necrosis factor a and
C-reactive protein are elevated in many cases. Because of similar symptoms, differential diagnosis is needed to confirm
CRMO from infectious
osteomyelitis, bone
tumors, and other diseases. The genetic component is likely in some cases such as
Majeed syndrome, deficiency of
IL-1 antagonist, etc. Imaging is the essential part of diagnosing
CRMO, and magnetic resonance imaging of the whole body is the most widely used and recommended method for the evaluation of multiple foci, as compared to radiography for reasons of sensitivity as well as prevention of excessive exposure of affected children to radiation.
CRMO is considered an autoimmune and auto-inflammatory disorder, but its precise pathophysiology is not clear. Current treatment options are non-
steroid anti-inflammatory drugs like
naproxen, as the primary choice, and the
bisphosphonates such as
pamidronate as the second choice, to counter the symptoms and to reduce bone lesions. The surgical option is the choice for recalcitrant cases, even though recurrence may still be a problem.