The Use of Infrared Cameras for Detecting Juvenile Idiopathic Arthritis

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.

Inclusion Criteria: * children aged 2-16 years with clinically suspected arthritis affecting the knee, ankle, wrist, or hand, irrespective of disease stage, * control group : children with non-inflammatory conditions and no history of autoimmune or inflammatory disease. Exclusion Criteria: * other inflammatory or non-inflammatory diseases or recent trauma/surgery explaining joint symptoms, * local skin conditions interfering with infrared imaging, and treatments or comorbidities likely to alter joint or body temperature.