AB0752 CHRONIC RECURRENT MULTIFOCAL OSTEOMYELITIS: A SINGLE-CENTER CASE SERIES

Background: Chronic recurrent multifocal osteomyelitis (CRMO) is a chronic autoinflammatory disease that primarily affects the skeleton of children and adolescents in absence an infectious etiology[1]. CRMO lesions presentation varies widely ranging from episodic bone pain to growth disturbance; lytic sclerotic can be found on X-ray, however magnetic resonance imaging very useful for evaluating extent follow-up [2]. Objectives: To report demographic, clinical laboratory characteristics response therapy single center Italian cohort patients. Methods: We reviewed retrospectively records seven patients affected by diagnosed between 2008 2019 at rheumatologic service South Tyrol region Italy. Results: identified 7 with CRMO, 4 were female patients, median age onset symptoms was years. Median delay diagnosis months; all had as initial symptom 6 presented joint swelling. number two; pattern, patient distribution 5 appendicular involvement. None our antinuclear antibodies or HLA-B27 positivity. Mean erythrocyte sedimentation rate 52 mm/h C-reactive protein 1,96 mg/dL. Regarding other organs involvement one palmoplantar pustulosis, psoriatic arthritis psoriasis guttata; three referred familiarity psoriasis. Histopathological confirmed 3 NSAIDs used six methotrexate two bisphosphonates Among biological DMARDs Adalimumab treated subsequently Secukinumab Ustekinumab. achieved remission (Table 1). Table 1. Demographic, osteomyelitis. Total (n=7 ) Demographics Female (%) (57) Age onset, years, (range) (6-24) Delay diagnosis, months, (2-14) Follow-up, 69 (11-151) Initial Bone pain, n (100) Swelling, (71) Limp, (43) Fever, 1 (14) Clinical features Number lesions, 2 (1-10) Axial involvement, (29) Appendicular Distribution Femur, Radius/ulna, Humerus, Tibia/fibula, (5) Tarsal bones, Others, Laboratory tests Hemoglobin, g/dL, mean ± SD 13.1±0.6 Leukocytes × 10 /mm , 8.48 ±1.7 Platelets 384±130 Erythrocyte mm/h, 52±37 protein, mg/dL, 1.96±2.35 Positive antibodies, 0 positive, Comorbidities Any type autoimmunity, Histological confirmation, Treatment NSAIDs, (86) Glucocorticoids, (0) Bisphosphonates, TNF blocking agents, Biological DMARDs, (4) Methotrexate, Antibiotics, Reached remission, Conclusion: remains rare diagnosis. From experience most showed mild elevation inflammatory parameters, association psoriasis, combination bisphosphonate immunosuppressive less than half References: [1]A. Taddio, F. Zennaro, S. Pastore, e R. Cimaz, «An Update Pathogenesis Recurrent Multifocal Osteomyelitis Children», Pediatr. Drugs vol. 19, n. 3, pagg. 165–172, giu. 2017. [2]S. J. Menashe et al. «The Many Faces Pediatric (CRMO): A Practical Location- Case-Based Approach Differentiate Its Mimics», Magn. Reson. Imaging JMRI pag. e27299, ago.2020 Disclosure Interests: declared