Objective. The aim of this study was to define the clinical utility of infrared thermography in disease activity detection in localized scleroderma (LS). Methods. We retrospectively reviewed 130 thermal images of 40 children with LS and calculated the sensitivity and specificity of thermography, comparing clinical descriptions of the lesions and contemporary thermographs. The reproducibility of thermography was calculated by using the weighted kappa coefficient to determine the level of agreement between two clinicians who reviewed the thermographs independently. Results. The sensitivity of thermography was 92% and specificity was 68%. Full concordance between the two clinicians was observed in 91% of lesions, with a kappa score of 0.82, implying very high reproducibility of this technique. Conclusion. Our results demonstrate that thermography is a promising diagnostic tool when associated with clinical examination in discriminating disease activity, as long as it is applied to lesions without severe atrophy of the skin and subcutaneous fat. Further evaluation is needed to determine whether thermography can predict the future progression of lesions.

/pdf/juvenile-onset-localized-scleroderma-activity-detection-by-qxrklk92j6.pdf

Juvenile‐onset localized scleroderma activity detection by infrared thermography

Although thermography has been used for a variety of abnormal conditions, extensive data on large, relatively asymptomatic populations has heretofore not been available. More specifically, no data deal with the upper extremities and, more particularly, no analyses are based on simultaneous thermograms of the posterior neck and shoulders. The current study undertook this task. The results confirm the existence of thermal symmetry in the overwhelming majority of 100 normal relatively asymptomatic, actively employed factory workers. Conversely, if persistent, statistically significant thermal asymmetry exists, as outlined and correlates with patient symptomatology, an organic basis for it should be sought.

Normal thermographic standards for the cervical spine and upper extremities.

Role of nitric oxide in the physiopathology of pain

The association between disease and human body temperature is as old as medicine itself. Hippocrates defined fever in different forms, such as malignant, benign and acute. It was claimed that if wet mud was applied to the skin, and one area dried rapidly while the remainder was still moist, that an underlying tumour may be suspected. It was not until Gallileo Gallilei developed his simple thermoscope in 1595 that attempts to measure temperature really began, and some hundred years later before closed thermometers and calibrated scales were used. Carl Wunderlich made the greatest progress in medicine by his development of the clinical thermometer and systematically recorded the progression of temperature in a large number of sick patients in 1871 [1]. His treatise On the Temperature in Disease carries a substantial section on temperature graphs from diseased patients, some with ‘rheumatic fever’. He argued for the routine measurement of temperature and that a graphic record be established for every patient. Following the work of Horvath and Hollander in the late 1940s [2], temperature measurements were used as a means of monitoring intra-articular steroid therapy by a number of authors. However, intra-articular temperature and isotope clearance techniques were invasive, unlike the infrared remote sensing techniques, which were available from the late 1950s. The story of infrared radiation began in 1800, when Sir William Herschel, the astronomer, detected heating rays beyond the visible red of the spectrum. After his death in 1840, his son John Herschel made the first thermal image from sunlight using the evaporograph technique. He used the term thermogram to describe the image, which is still in common use today [3]. Early infrared imaging systems were developed during the 1940s and became available to industry and medicine first in 1959. The Pyroscan (a 1942 instrument) was first used in Bath in 1959 (Fig. 1) and was used to image the increased heat over arthritic joints. Picture quality improved with the Mark 2 instrument (Fig. 2), although each image took 3–4 minutes to acquire and was almost impossible to quantify. Later, with improved equipment, better dynamic (and objective images) were obtained that could usefully supplement radiological investigation [4].

The historical development of thermal imaging in medicine.

We have identified regular thermal patterns over normal knee, ankle, and elbow joints and demonstrate how synovitis affecting these joints may be identified by alteration or loss of the thermal pattern. Sixty healthy volunteers were thermographed on a total of 190 occasions, and 614 out of 618 joints conformed to the normal thermal pattern. Eighty-five patients with synovitis of at least one of the specified joints were thermographed on a total of 339 occasions, and 322 out of 1362 thermograms were abnormal. No joint with clinical evidence of synovitis had a normal thermal pattern. As temperature-based parameters have been found to show marked diurnal variation and relative frequency distributions do not have this drawback, we suggest that quantification of synovitis by thermography should in future be based on abnormalities of thermal pattern rather than absolute skin temperature values.

https://ard.bmj.com/content/annrheumdis/42/5/494.full.pdf

Joan D. Brookshaw

Papers

Thermography and radiology complimentary methods for the study of inflammatory diseases