Does Thermal Imaging Correlate With Musculoskeletal Examination in the Identification of Inflamed Joints in Children and Young People With Juvenile Idiopathic Arthritis? A Prospective Diagnostic Accuracy Study

Childhood arthritis is a diagnosis made by clinicians based upon their clinical examination, during which patients are assessed for signs of swelling, warmth and restricted movement of the joints using the sensation of touch. Clinicians use investigations such as blood tests and scans which may be costly, associated with waiting times, can cause the patient stress or anxiety. Patients with childhood arthritis can often present with flares of their condition even when on medical treatment, which may require further investigations to determine the nature of the problem. Studies in adult Rheumatology have demonstrated that a thermal imaging camera (which detects heat given off by the body) can be useful in assessing for signs of inflammation in arthritis. The use of this camera could provide an alternative to the tests described; it does not require any contact with the patient, is quick and easy to use, and does not emit any radiation. The investigators hope that this pilot study will demonstrate that thermal imaging can be used to complement the standardised assessments of joint inflammation as done routinely in clinic and may lead to further work comparing thermal imaging with other tests such as MRI scanning and ultra-sound.

The investigators will recruit 20-50 children with arthritis affecting either knee or ankle joints. The investigators will use a highly sensitive thermal imaging camera to take pictures and short video recordings of each ankle and knee joint, recording skin temperature and colour. The investigators will compare this with the clinicians' assessment of whether the knee and ankle joints are inflamed or not. The investigators are interested in finding out whether the information recorded using the camera mirrors the assessment made by the clinician.