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

Wound area severity index (WASI): A novel tool for assessing and predicting healing times in hidradenitis suppurativa postsurgical wounds

Hidradenitis suppurativa (HS) presents challenges in management due to its chronic nature and high risk of recurrence. Post-surgical wound care plays a crucial role in treatment, even if standardized methods for assessing and predicting healing times are lacking. The aim of the study is to introduce the Wound Area Severity Index (WASI) as a novel tool to guide clinicians in assessing postsurgical wound progression and predicting potential healing times. A team of wound healing experts assessed 93 post-surgical HS wounds resulting from wide excision and secondary intention healing. For each wound healing time, wound area, wound bed score (WBS), and WASI were evaluated. WASI includes four parameters: area, temperature, depth and wound Bed, each with four severity levels. The total WASI score ranges from 4 to 16. Spearman correlation and Kruskal-Wallis tests were employed for statistical analysis. WASI strongly correlated with wound healing time (rho: 0.813, p < 0.001). Higher WASI scores were associated with prolonged healing, while lower scores indicated almost healed wounds. The WASI score has proven to be more highly predictive of healing times when compared to the individual parameter of the Area (moderate positive correlation, r: 0.77) and the WBS (negative correlation, r: -0.72). A total WASI score of 4 corresponded to a median healing time of 7 days, while a score exceeding 9 suggested a median healing time of 56 days. WASI has proven to be a valuable tool for assessing and predicting healing times in post-surgical HS wounds. Its simplicity, cost-effectiveness, and ability to integrate multiple parameters make it a promising addition to wound care practice.

S2k‐Leitlinie zur Therapie der Hidradenitis suppurativa/Acne inversa – Kurzfassung

Die S2k‐Leitlinie der Hidradenitis suppurativa/Acne inversa (HS/AI) soll eine akzeptierte Entscheidungshilfe für die Auswahl/Durchführung einer geeigneten/suffizienten Therapie liefern. Hidradenitis suppurativa/Acne inversa ist eine chronisch‐rezidivierende, entzündliche, potenziell mutilierende Hauterkrankung des terminalen Haartalgdrüsenapparats, mit schmerzhaften, entzündlichen Läsionen in den apokrinen drüsenreichen Körperregionen. Ihre Punktprävalenz in Deutschland ist 0,3%, sie wird mit einer Verspätung von 10,0 ± 9,6 Jahren diagnostiziert. Abnormale Differenzierung der Keratinozyten des Haartalgdrüsenapparats und eine begleitende Entzündung bilden die zentrale pathogenetische Grundlage. Primäre HS/AI‐Läsionen sind entzündliche Knoten, Abszesse und drainierende Tunnel. Rezidive in den letzten 6 Monaten mit mindestens zwei Läsionen an den Prädilektionsstellen verweisen auf eine HS/AI mit einer 97‐prozentigen Genauigkeit. HS/AI‐Patienten leiden an einer deutlichen Einschränkung der Lebensqualität. Zur korrekten Therapieentscheidung sollen Klassifikation und Aktivitätsbewertung mit einem validierten Instrument erfolgen, wie dem International Hidradenitis Suppurativa Severity Scoring System (IHS4). Hidradenitis suppurativa/Acne inversa wird nach der Ausprägung der nachweisbaren Entzündung in zwei Formen eingeteilt: aktive, entzündliche (milde, mittelschwere und schwere nach IHS4) und vorwiegend inaktive, nicht entzündliche (Hurley‐Grad‐I, ‐II und ‐III) HS/AI. Orale Tetrazykline oder eine 5‐tägige intravenöse Therapie mit Clindamycin sind mit der Effektivität von Clindamycin/Rifampicin vergleichbar. Subkutan applizierbares Adalimumab, Secukinumab und Bimekizumab sind für die Therapie der HS/AI zugelassen. Für die vorwiegend nicht entzündliche Erkrankungsform stehen verschiedene operative Verfahren zur Verfügung. Medikamentöse/chirurgische Kombinationen gelten als ganzheitliches Therapieverfahren.

S2k guideline for the treatment of hidradenitis suppurativa / acne inversa - Short version

The S2k guideline on hidradenitis suppurativa/acne inversa (HS/AI) aims to provide an accepted decision aid for the selection/implementation of appropriate/sufficient therapy. HS/AI is a chronic recurrent, inflammatory, potentially mutilating skin disease of the terminal hair follicle-glandular apparatus, with painful, inflammatory lesions in the apocrine gland-rich regions of the body. Its point prevalence in Germany is 0.3%, it is diagnosed with a delay of 10.0 ± 9.6 years. Abnormal differentiation of the keratinocytes of the hair follicle-gland apparatus and accompanying inflammation form the central pathogenetic basis. Primary HS/AI lesions are inflammatory nodules, abscesses and draining tunnels. Recurrences in the last 6 months with at least 2 lesions at the predilection sites point to HS/AI with a 97% accuracy. HS/AI patients suffer from a significant reduction in quality of life. For correct treatment decisions, classification and activity assessment should be done with a validated tool, such as the International Hidradenitis Suppurativa Severity Scoring System (IHS4). HS/AI is classified into two forms according to the degree of detectable inflammation: active, inflammatory (mild, moderate, and severe according to IHS4) and predominantly inactive, non-inflammatory (Hurley grade I, II and III) HS/AI. Oral tetracyclines or 5-day intravenous therapy with clindamycin are equal to the effectiveness of clindamycin/rifampicin. Subcutaneously administered adalimumab, secukinumab and bimekizumab are approved for the therapy of HS/AI. Various surgical procedures are available for the predominantly non-inflammatory disease form. Drug/surgical combinations are considered a holistic therapy method.

Beyond visual inspection: The value of infrared thermography in skin diseases, a scoping review

Although warmth is a key sign of inflammatory skin lesions, an objective assessment and follow-up of the temperature changes are rarely done in dermatology. The recent availability of accurate, sensitive and cost-effective thermography devices has made the implementation of thermography in clinical settings feasible. The aim of this scoping review is to summarize the evidence around the value and pitfalls of infrared thermography (IRT) when used in the dermatology clinic. A systematic literature search was done for original articles using IRT in skin disorders. The results concerning the potential of IRT for diagnosis, severity staging and monitoring of skin diseases were collected. The data on the sensitivity and specificity of IRT were extracted. Numerous studies have investigated IRT in various skin diseases, revealing its significant value in wound management, skin infections (e.g. cellulitis), vascular abnormalities and deep skin inflammation (e.g. hidradenitis suppurativa). For other dermatological applications such as the interpretation of intradermal and patch allergy testing, hyper-/anhidrosis, erythromelalgia, cold urticaria and lymph node metastases more complex calculations, provocation tests or active cooling procedures are required. Dermatologists should be aware of a learning curve of IRT and recognize factors contributing to false positive and false negative results. Nonetheless, enough evidence is available to recommend IRT as a supplement to the clinical evaluation for the diagnosis, severity and follow-up of several skin diseases.

The role of imaging technologies in the diagnosis of hidradenitis suppurativa

Hidradenitis suppurativa is a chronic, inflammatory, recurrent, and debilitating disease of the hair follicle. It presents with painful, deep-seated, inflamed lesions, such as nodules, abscesses, sinus tracts, and fistulas, generally located in the main folds. Clinical severity assessment alone can be reductive; noninvasive skin imaging technologies, such as ultrasound, magnetic resonance imaging, medical infrared thermography, computed tomography, and positron emission tomography, provide subclinical anatomical and functional details. These instrumental techniques confirm the clinical suspect, thus allowing an earlier diagnosis and improving patients' clinical evaluation, staging, and management. Finally, they might be helpful for preoperative mapping. In this contribution, we provide an overview of the current knowledge about noninvasive skin imaging techniques with a particular focus on ultrasonography, which is widely used thanks to its precision, versatility, and availability.

Infrared Thermography in Wound Care, Surgery, and Sports Medicine: A Review

For many years, the role of thermometry was limited to systemic (core body temperature) measurements (e.g., pulmonary catheter) or its approximation using skin/mucosa (e.g., axillary, oral, or rectal) temperature measurements. With recent advances in material science and technology, thermal measurements went beyond core body temperature measurements and found their way in many medical specialties. The article consists of two primary parts. In the first part we overviewed current clinical thermal measurement technologies across two dimensions: (a) direct vs. indirect and (b) single-point vs. multiple-point temperature measurements. In the second part, we focus primarily on clinical applications in wound care, surgery, and sports medicine. The primary focus here is the thermographic imaging modality. However, other thermal modalities are included where relevant for these clinical applications. The literature review identified two primary use scenarios for thermographic imaging: inflammation-based and perfusion-based. These scenarios rely on local (topical) temperature measurements, which are different from systemic (core body temperature) measurements. Quantifying these types of diseases benefits from thermographic imaging of an area in contrast to single-point measurements. The wide adoption of the technology would be accelerated by larger studies supporting the clinical utility of thermography.

Evaluation of skin using infrared thermal imaging for dermatology and aesthetic applications

INTRODUCTION

The use of thermography in the medical field has been experiencing a renaissance due to advances in the infrared thermographic imaging technology, which improves thermographic equipment and promises cost saving and increased safety. Dermatology is one of the most promising fields of application among the medical areas with potential for the use of thermography.

OBJECTIVE

To review the findings on this subject and to describe the use of such technique for dermatology and aesthetic applications.

METHODS

A bibliographic survey was carried out, selecting relevant publications and guidelines, focused on monitoring medical diagnostic applications and benefits of thermography for dermatology, inflammatory skin diseases, and aesthetic applications.

RESULTS

Inflammatory skin diseases lead to changes of the IRT image. A quantification of treatment effects and monitoring changes on skin can be possible by repeated measurements over time.

CONCLUSION

Infrared imaging is a noninvasive, powerful tool in the diagnosis and clinical management of skin conditions and monitoring of aesthetic procedures.

Medical infrared thermography as hidradenitis suppurativa diagnostic tool: literature review

Hidradenitis suppurativa (HS) is a rare, chronic, inflammatory skin disease that has a strong impact on the quality of life. Medical infrared thermography (MIT) is a non-invasive imaging method that could be used for evaluation of skin inflammation, which is an important biomarker in HS. We performed a comprehensive review of the literature to verify the possibilities of using MIT for HS. Key words “hidradenitis suppurativa”, “acne inversa” and “thermography” were used for PubMed, Embase and Scopus literature analysis and in total four articles fulfilled the inclusion criteria. The inflamed areas have shown the increase in temperature (34.3°C) and after the removal of lesions the temperature has become similar to the healthy skin sites. The margins of the inflammatory lesions identified by MIT were used in the surgical treatment. Also, MIT was used in combination with other imaging tests for inflammation evaluation. Thermography is an advantageous tool to detect inflammation and to secure the success of surgical treatment.

Quality of Life in Hidradenitis Suppurativa: An Update

Knowledge on hidradenitis suppurativa/acne inversa (HS) is rapidly increasing. HS has a profound impact on patients and their family life. Several factors, such as comorbidities, unemployment and HS severity, make this impact even more severe. The most widely used instrument to measure this impact is the dermatology-specific DLQI. We also identified six HS-specific health-related quality of life (HRQoL) instruments. Of them, HIDRAdisk, HSIA, HiSQOL and HSQoL-24 are better validated but there is still lack of experience of its use. Several treatment methods showed positive effect on patients’ HRQoL. Surgery remains a method with a substantial positive effect on HRQoL. Several studies confirming a positive effect of adalimumab on the HRQoL of patients with HS were published during the last three years. Data on the influence of several other biologics on HRQoL of HS patients are controversial or based on studies with a small number of patients.

Diagnostic accuracy of infrared thermal imaging for detecting COVID-19 infection in minimally symptomatic patients

INTRODUCTION

Despite being widely used as a screening tool, a rigorous scientific evaluation of infrared thermography for the diagnosis of minimally symptomatic patients suspected of having COVID-19 infection has not been performed.

METHODS

A consecutive sample of 60 adult individuals with a history of close contact with COVID-19 infected individuals and mild respiratory symptoms for less than 7 days and 20 confirmed COVID-19 negative healthy volunteers were enrolled in the study. Infrared thermograms of the face were obtained with a mobile camera, and RT-PCR was used as the reference standard test to diagnose COVID-19 infection. Temperature values and distribution of the face of healthy volunteers and patients with and without COVID-19 infection were then compared.

RESULTS

Thirty-four patients had an RT-PCR confirmed diagnosis of COVID-19 and 26 had negative test results. The temperature asymmetry between the lacrimal caruncles and the forehead was significantly higher in COVID-19 positive individuals. Through a random forest analysis, a cut-off value of 0.55°C was found to discriminate with an 82% accuracy between patients with and without COVID-19 confirmed infection.

CONCLUSIONS

Among adults with a history of COVID-19 exposure and mild respiratory symptoms, a temperature asymmetry of ≥ 0.55°C between the lacrimal caruncle and the forehead is highly suggestive of COVID-19 infection. This finding questions the widespread use of the measurement of absolute temperature values of the forehead as a COVID-19 screening tool.

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

Background: The development of imaging-based biomarkers has the potential to overcome major challenges in the accurate and reproducible assessment of disease severity and response to novel therapies in Hidradenitis Suppurativa (HS). Understanding the advantages and limitations of existing non-invasive imaging modalities in dermatological disease will aid in the development of hypotheses and inform the design of future studies. Methods: A scoping review was performed using Medline, Embase, Web of Science Databases and evaluation of "gray literature" until June 30, 2019. Citations were examined according to pre-defined inclusion and exclusion criteria. Citations were reviewed by two independent reviewers. Narrative Synthesis was used to summarize data, structured by imaging modality. Results: Non-invasive imaging modalities, such as ultrasound, MRI, RCM, EIS, OCT, and MIT, were identified. Only ultrasound, MRI and MIT have been used in HS. Image modalities vary in image depth, resolution, cost, accessibility and correlation with known aspects of disease activity in HS. Discussion and Conclusion: The benefits and limitations of each imaging modality are products of cost, accessibility, validity and reliability. An additional hurdle to the development of image-based biomarkers in HS is a lack of established analytical benchmarks that can be correlated with existing biological, inflammatory and clinical parameters. This review has identified potential imaging biomarkers, as well as relevant analytical benchmarks that reflect the presence or absence of disease. Further investigation work is needed to analytically and clinically validate these imaging variables in order to identify potential imaging biomarkers in HS.

Review of imaging technologies used in Hidradenitis Suppurativa

BACKGROUND

Until recently, clinical assessment with manual palpation of the HS lesions was the primary means to detect HS lesions and their borders. In the past decade, there has been increased application of imaging technologies to HS patients, and it is reported that manual palpation consistently underestimates HS. Of the technologies, ultrasound (US) imaging has been the most efficacious and well-studied. In the present review, we will discuss the various imaging modalities that aid in detecting, managing, and treating HS.

MATERIALS AND METHODS

Non-invasive HS imaging technologies including ultrasound (US) imaging, magnetic resonance imaging (MRI), medical infrared thermography (MIT), positron emission topography (PET), and computed tomography (CT) were reviewed and compared through a review of the literature. PubMed, Google, and Google Scholar were utilized.

RESULTS

Of the 4 HS technologies reviewed, US imaging and MRI are the most established and useful non-invasive modalities utilized in HS patients. However, MIT may have potential to aid in the pre-operative and intra-operative surgical excision of HS lesions.

CONCLUSION

For imaging HS lesions, US imaging is the most well-characterized and has the greatest range of use, while MRI has a role in severe, anogenital HS lesions. MIT of HS lesions is a novel application and merits attention.