Long-Wave Medical Infrared Thermography: A Clinical Biomarker of Inflammation in Hidradenitis Suppurativa/Acne Inversa

Abstract

Background: A more reliable classification of skin inflammation and severity of active disease results from ultrasound sonography and the new hidradenitis suppurativa/acne inversa (HS) classification system IHS4. However, an objective assessment of skin inflammation in a continuous mode is still the ultimate goal. Long-wave medical infrared thermography (MIT) may offer a blood flow and temperature differential assessment in inflammatory conditions. Objective: To evaluate the application of MIT in HS. Methods: Standardized photography of the areas involved or been candidates for HS involvement was performed and MIT pictures were taken simultaneously and superimposed on the photographs of 18 patients (11 female, 7 male, median age 38.75 years [95% confidence interval 28.5 and 51 years], Hurley score I 5.6%, Hurley score II 38.9%, and Hurley score III 55.5%). A modification of the Otsu’s method facilitated the automatic lesion segmentation from the background, depicting the inflammation area. Moreover, MIT was administered in real-time mode during radical HS surgery. Results: A 1°C temperature difference from a corresponding symmetric body region was indicative of inflammation. MIT figures detected a gradual increase of skin temperature from 33.0°C in healthy skin on average to 35.0–36.6°C at the center of inflamma tory lesions in the axilla and to 35.4–36.9°C at the center of inflammation in the groin area. Real-time MIT assessment enabled the definition of the margins and depth of the surgical intervention during the procedure. Conclusion: MIT is a promising tool for the detection of inflammation severity in HS lesions and can be used as a clinical biomarker in evaluation studies of medical and surgical HS treatment.

What causes hidradenitis suppurativa ?—15 years after

“…Robust ex vivo models might corroborate clinical data. 197 Clearer documentation and newer diagnostic techniques, such as standardized photography, ultrasound and thermography 66,[198][199][200]…”

A Scoping Review of Non-invasive Imaging Modalities in Dermatological Disease: Potential Novel Biomarkers in Hidradenitis Suppurativa

“…MIT has assessed burn wound depth (66) and is being actively investigated as an alternative to ultrasound in the grading of HS. MIT has been correlated with qualitative changes in Doppler blood flow in HS (67) and have defined tissue margins in HS skin removal surgery (67, 68). It remains unclear whether the accuracy and reproducibility of MIT is influenced by body site, previous surgical excisions and microvascular disease from smoking and/or metabolic syndrome, which may all influence tissue blood flow (69).…”

Review of imaging technologies used in Hidradenitis Suppurativa

“…MIT does not cause pain to HS patients, is relatively fast, and is highly temperature‐sensitive with adequate spatial resolution . Recently, MIT has been utilized to detect HS as it can detect the associated inflammation . First, MIT has been shown to be helpful as a supplementary assessment during surgical resection of an HS lesion after pre‐surgical MRI.…”

“…It was demonstrated that a 1°C temperature difference between skin areas corresponded to HS inflammation. Objectively, MIT displayed healthy skin as 33°C areas whereas HS‐affected, and thus generally inflamed, areas averaged 35°C or above . However, as MIT detects differences in temperature, it can only detect inflamed HS lesions and has no utility in the detection of non‐inflamed sinus tracts or in patients with co‐localized inflammation due to another cause.…”