PT - JOURNAL ARTICLE AU - Ross Fraleigh AU - Xing-Chang Wei AU - Weiming Yu AU - Paivi Maria Miettunen TI - Chronic recurrent multifocal osteomyelitis with a comprehensive approach to differential diagnosis of paediatric skull pain AID - 10.1136/bcr-2022-252471 DP - 2023 Jan 01 TA - BMJ Case Reports PG - e252471 VI - 16 IP - 1 4099 - http://casereports.bmj.com/content/16/1/e252471.short 4100 - http://casereports.bmj.com/content/16/1/e252471.full SO - BMJ Case Reports2023 Jan 01; 16 AB - A girl in middle childhood was referred to rheumatology with a 1-month history of progressive skull pain, preceded by fleeting musculoskeletal symptoms. Apart from a scaly rash on her scalp, she was well, with moderately elevated inflammatory markers. Skull imaging (radiographs, CT and MRI) revealed osteolytic lesions, soft tissue swelling and pachymeningeal enhancement at frontal and temporal convexities. Langerhans cell histiocytosis, bone infection/inflammation or malignancy was considered. Skin and bone biopsies eventually ruled out mimicking diseases and confirmed the diagnosis of chronic recurrent multifocal osteomyelitis (CRMO). She was treated with intravenous pamidronate (IVPAM) for 9 months, with rapid resolution of pain and gradual resolution of bony abnormalities. She remains in remission at 15-month follow-up. While CRMO can affect any bone, skull involvement is extremely rare, with a broad differential diagnosis. We recommend bone biopsy to confirm skull CRMO. The patient achieved excellent clinical and radiological response to IVPAM.