Thermography hand temperature distribution in rheumatoid arthritis and osteoarthritis

Background and Purpose: Earliest written medical text from ancient Egypt mentioned temperature as an indicator of a disease. Although already known, thermal imaging has not been routinely used in medicine. Inflammation of peripheral joints, close to skin surface, is the dominant type of presentation of rheumatoid arthritis and due to that, those joints are suitable for infrared thermal scanning. Considering the changes of the bones in the affected joints, as a control group, apart from healthy subjects, study was conducted on patients with osteoarthritis as well. Purpose of this paper was to investigate thermal images of the hands of patients with rheumatoid arthritis and osteoarthritis and analyze temperature distribution. Materials and Methods: Thermographic images of both hands of healthy subjects, patients with rheumatoid arthritis and patients with osteoarthritis were made. On thermal images obtained, temperature distribution of certain regions was analyzed. Basic statistical analyses (minimum, maximum, standard deviation, mean, and variance) were performed. Results: There is a statistically significant difference in finger and metacarpophalangeal joint mean temperature values on ventral and dorsal sides for both healthy patients and patients with rheumatoid arthritis and osteoarthritis. Also, there is a statistically significant difference of mean temperature values between the aforementioned patient groups. Temperature distribution curves of patients with osteoarthritis have been narrower than those of subjects with rheumatoid arthritis and normal subjects. Temperature distribution curves of patients with rheumatoid arthritis have been shifted towards higher temperatures than those of subjects with osteoartritis and normal subjects. Conclusion: From the results obtained it was concluded that heat distribution over the skin surface apart from depending on the affected joint and on the intensity of the disease and given drug therapy also differs between the patients with rheumatoid arthritis and osteoarthritis, making the use of thermography a possible method of differentiating normal subjects and rheumatoid arthritis subjects and osteoarthritis subjects from each other: