The Childhood Arthritis & Rheumatology Research Alliance (CARRA) Registry is a special collection of information about children who have rheumatic diseases. Rheumatic diseases are illnesses that cause pain and swelling in the joints or muscles. This study helps doctors and researchers learn more about how to treat these diseases safely and better understand how they affect children. It's an observational study, meaning it collects information without changing how patients are treated. The study aims to follow each participant for up to 10 years, but it may go on longer if needed. It uses this information to answer important questions about the safety and effectiveness of different treatments. The Duke Clinical Research Institute manages the data for this study. Children who developed a rheumatic disease before age 16 (or before 19 for other diseases) can join. They or their parents must agree to the study rules and be okay with being contacted by the study team.

• Participants may be followed for up to 10 years.
• No treatment changes are required; it's observational.
• Gives a chance to help improve future treatment options.