Long-wave Medical Infrared Thermography assessment of inflammation in hidradenitis suppurativa/acne inversa

Christos C. Zouboulis1,2, André Nogueira da Costa3, Gregor B.E. Jemec2,4, Dietrich Trebing1

1Departments of Dermatology, Venereology, Allergology and Immunology, Dessau Medical Center, Brandenburg Medical School Theodor Fontane, Dessau, Germany
2European Hidradenitis Suppurativa Foundation e.V.
3Translational Medicine, UCB BioPharma SPRL, Braine L'Alleud, Belgium
4Department of Dermatology, Zealand University Hospital, University of Copenhagen, Roskilde, Denmark

A more reliable classification of skin inflammation and severity of active disease results by ultrasound sonography and the new 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. This project was designed to evaluate the application of MIT in HS. Standardised photography of the areas involved or been candidate for HS involvement and MIT pictures of 18 patients [11 female, 7 male, median age 38.75 years (95% confidence intervals 28.5 and 51 years), Hurley score I 5.6%, Hurley score II 38.9% and Hurley score III 55.5%] were taken subsequently with a FLIR T650sc Thermography Imaging Unit at a distance of 50 cm from the skin surface and the pictures were superimposed. 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. 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 in average to 35.0-36.6°C at the center of inflammatory lesions in the axilla and to 35.4-36.9°C at the center of inflammation at the groin area. Real-time MIT assessment enabled the definition of the margins and depth of the surgical intervention during the procedure. In conclusion, MIT is a promising tool for detection of inflammation severity in HS lesions and can be used as a clinical biomarker in evaluation studies of medical and surgical HS treatment.