CHronic Nonbacterial Osteomyelitis International Registry

The CHronic Nonbacterial Osteomyelitis (CNO) International Registry collects data on children and young people with CNO — a rare inflammatory bone disease where the immune system attacks bone tissue without any bacterial infection. Because CNO is uncommon, having an international registry allows researchers to study enough cases to understand how it behaves and how it should be treated. Participants will have their medical records, imaging scans, and treatment outcomes entered into the registry. This is an observational study — no experimental treatment is given. The data will help identify what works best for managing CNO. You may be eligible if: - You are 21 years old or younger at the time of enrollment - You have bone edema seen on MRI within 12 weeks of enrollment - You have had a full-body imaging evaluation (whole-body MRI or bone scan) - A bone biopsy has been done to rule out infection or cancer (unless typical disease distribution or associated conditions like IBD, psoriasis, or palmar plantar pustulosis are present) You may NOT be eligible if: - You have a current or past history of malignancy (cancer) - You have active infectious osteomyelitis - There is a contraindication to the treatment being used Talk to your doctor to see if this trial is right for you.