A complicated path to the CRMO diagnosis – case of a 9 year old girl whose story comes full circle

BACKGROUND: Chronic recurrent multifocal osteomyelitis (CRMO) is a rare idiopathic autoinflammatory bone disease that mostly affects children and adolescents. It is a diagnosis of exclusions since no clinical signs and symptoms are pathognomonic. Radiological tests are often essential, but bone biopsy may be needed in unclear cases. CASE PRESENTATION: A 9-year-old Caucasian girl with a history of bone pain. The data from the history and results of laboratory tests suggested osteomyelitis, but no adequate response to the treatment was observed. A number of imaging tests did not confirm the diagnosis, therefore a bone biopsy was necessary. CONCLUSIONS: Differential diagnosis of CRMO is challenging and it is based on exclusions. Since it might be misdiagnosed or mistreated, bone biopsy should be considered in patients reporting bone pain who are unresponsive to treatment.