The Use of Infrared Cameras for Detecting Juvenile Idiopathic Arthritis (InfraAJI)

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children, causing persistent joint inflammation, pain, and functional impairment. Current monitoring relies on clinical scores, laboratory markers, and imaging, which are often resource intensive. Infrared thermography (IRT) is a non-invasive, radiation-free method that detects skin temperature changes potentially reflecting joint inflammation. Evidence in pediatric populations is limited, but IRT could provide an objective, reproducible, and child-friendly tool. This study aims to evaluate IRT's diagnostic accuracy by comparing it with clinical scores, laboratory markers, and ultrasound Doppler, to assess its utility as a complementary monitoring tool.

Patients with JIA will undergo clinical examination, routine blood tests, and IRT at baseline, 1 month, and 3 months. Control patients will participate in a single IRT session and, a CRP/ESR/blood test; if a biological workup is already planned as part of their routine care, existing results will be collected, and no additional sampling will be performed. IRT will follow a standardized protocol, including an acclimatization period, predefined positioning, and acquisition of three consecutive images per joint. After completion of the study, JIA patients will resume their standard-of-care follow-up.