Update on Ultrasound Diagnostic Criteria and New Ultrasound Severity and Activity Scorings of Hidradenitis Suppurativa: Modified SOS-HS and US-HSA.

Hidradenitis suppurativa (HS) is a devasting autoimmune cutaneous disease that affects the hair follicles and can clinically present palpable nodules, abscesses, and tunnels (fistulas), usually in the intertriginous regions. It has been widely reported that color Doppler ultrasound can detect subclinical abnormalities and stage the severity of the disease more accurately. Nevertheless, the ultrasound diagnostic criteria were reported with 15 MHz 10 years ago, and now it is possible to detect early anatomical abnormalities in HS using 70 MHz. Thus, an update of the ultrasonographic diagnostic criteria is needed. The most widely used sonographic staging of severity of HS (SOS-HS) includes the number of affected regions, besides counting the number of key lesions like pseudocysts, fluid collections, and tunnels; however, the total number of affected regions may fit better in an activity scoring. Furthermore, a high number of tunnels or communicated tunnels can complicate the management and may indicate an even more urgent treatment, which should be considered in the severity classification. To date, no hidradenitis scoring of activity has been reported in the literature, making it difficult to track the degree of inflammation under treatment objectively. Therefore, two new scorings are proposed. The first is an updated sonographic scoring of severity called modified SOS-HS (mSOS-HS), and the second is an activity ultrasound scoring of HS called US-HSA. Both staging systems can provide better anatomical information for discriminating the categories and, therefore, selecting more appropriate treatments and supporting research and clinical trials by giving more objective anatomical tools in real-world settings.

Automated classification of hidradenitis suppurativa disease severity by convolutional neural network analyses using calibrated clinical images.

BACKGROUND: The assessment of hidradenitis suppurativa (HS) severity requires detailed, and error-prone lesion counts. This proof-of-concept study aimed to automatically classify HS disease severity using machine learning of clinical smartphone images. METHODS: 777 ambient-light and size-controlled images were used to build a class-balanced synthetic dataset (n = 7675). Convolutional neural networks (CNN) were used for automated severity classification (scale 0-3), and to assess disease-dynamics. International Hidradenitis Suppurativa Severity Score System (IHS4) served as reference. A U-NET algorithm was implemented for automated localization of diseased skin. RESULTS: CNNs were able to distinguish no/mild from moderate/severe disease with an overall prediction accuracy of 78% [receiver operating curve (AUC) 0.85]. Correct IHS4 classification was achieved with an overall accuracy of 72% (AUC 0.84-0.89). In addition, disease dynamics using IHS4 numerical values aligned with CNN outputs (NRMSE 0.262). The UNET algorithm localized lesions with a pixel accuracy of 88.1% and test loss of 0.42. LIMITATIONS: Limitations in assessing tattooed and hairy skin. Limited number of patients with dark skin colour and Hurley I. CONCLUSION: CNNs were able to distinguish no/mild from moderate/severe disease, classify disease severity over time, and automatically identify diseased skin areas and the skin phototype. This study breaks new grounds for fast, reliable, reproducible and easy-to-use HS severity assessments using clinical images.

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.

The use of ultrasound and magnetic resonance imaging in the management of hidradenitis suppurativa: a narrative review.

Hidradenitis suppurativa (HS) is a chronic, inflammatory follicular skin disease that frequently affects the apocrine gland-bearing skin of the axillary, inguinal and anogenital regions. HS has a significant impact on the psychosocial health and quality of life of patients. Diagnosis of HS is typically clinical, and relies on the ability of physicians to recognize the signs of HS. However, lesions may present at the dermal and subcutaneous skin layers, which cannot be diagnosed by clinical examination alone. Further, the complexity of the clinical presentation of HS can lead to misdiagnosis and delay of diagnosis and appropriate treatment. Imaging is an important tool that can address these issues by detecting inflammatory activity and the early subclinical and dermal features of HS, and accurately characterizing lesional morphology, thereby informing on optimal therapeutic strategies. Overall, imaging is a key tool that can be used in conjunction with clinical examination to improve the management of HS by providing additional information to physicians, and thus optimize clinical decision making. In this narrative review, we provide an overview of the general role of imaging in the management of HS, and we illustrate HS-specific applications of two pertinent imaging modalities, ultrasound and magnetic resonance imaging. Finally, based on the literature, we summarize their uses in HS and provide considerations relating to standardizing the practise of ultrasound and effectively implementing the use of imaging in the management of HS.

Can Ultrasound Examinations Generate Pain in Hidradenitis Suppurativa Patients? Results from a Multicentric Cross-Sectional Study.

BACKGROUND: Pain is not a trivial issue for hidradenitis suppurativa (HS) patients and has been considered a domain in the Core Outcome Set. To date, there is no evidence about pain caused by the ultrasound examinations. OBJECTIVE: The aim of the study was to assess the presence of pain generated by the ultrasound examinations of HS patients. METHODS: A multicentric cross-sectional study for detecting pain during the ultrasound examinations of HS patients using a validated verbal questionnaire immediately after the imaging studies. Statistical analysis included demographic data and possible associations with sex, age, location, clinical (Hurley), and ultrasonographic scoring (SOS-HS). The statistical tests were two proportions Z test, χ2 test, Student's t test, and ANOVA. A p < 0.05 was considered significant. RESULTS: 317 patients met the criteria. 77.3% of them did not present pain. Of cases with pain, 59.8% were mild, 16.7% moderate, and 23.6% severe. No significant association was found with sex, age, staging, location, or the number of affected regions. Although nonsignificant, severe pain cases were more frequent in the clinical Hurley III and ultrasonographic SOS-HS III stages. CONCLUSION: Pain generated by the ultrasound examination of HS patients is infrequent.

Magnetic Resonance Imaging of Hidradenitis Suppurativa: A Focus on the Anoperineal Location.

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease involving apocrine-bearing sites. It is characterized by recurrent painful nodules and abscesses that potentially rupture, resulting in sinus tract formation, fistulas, and scarring. HS tends to be found in the intertriginous areas (i.e., the axillary, inguinal, and perianal areas of the body). HS may be uncommon for radiologists because its diagnosis is usually based on clinical assessment. However, diagnosis based solely on clinical manifestations can underestimate the severity of HS. Ultrasonography and MRI play a critical adjunct role in determining the severity and extent of the disease and greatly aid its management. Given that MRI is an effective imaging tool, its role in the analysis of severe and anogenital HS lesions merits considerable attention. Unfortunately, anoperineal HS imposes diagnostic dilemmas. It has multiple symptoms and presentations and often mimics other diseases in the intertriginous areas. Therefore, a thorough understanding of HS is essential to avoid delayed diagnoses. This review highlights the typical MRI imaging features and staging of HS, emphasizing on the anoperineal location. The review also differentiates the disease from mimics to facilitate the prompt delivery of appropriate treatment and improve patients' quality of life.

Hidradenitis suppurativa: Morphologic and vascular study of nodular inflammatory lesions by means of optical coherence tomography.

Hidradenitis suppurativa (HS) is an inflammatory disease characterized by a recurrent-remission trend and clinical lesions that range from asymptomatic to inflamed, deep-seated nodules with scarring and suppuration. The aim of our study was to identify morphologic and vascular features of HS nodules by means of dynamic optical coherence tomography (D-OCT) and to define if they are correlated to patient endotype and risk of disease progression. A set of standardized clinical pictures and D-OCT images were acquired from 57 inflammatory nodules of 40 patients affected by HS. A set of 20 clinical and D-OCT images were acquired from 20 healthy volunteers as a control group. The comparison of D-OCT features among HS and control group was analysed. The correlation between HS patient endotype and D-OCT features of the lesions was calculated. D-OCT enabled to identify vascular and morphological aspects characterizing HS nodular inflammatory lesions. In addition, several D-OCT features were significantly different among distinct disease endotypes. The characterization of HS nodular inflammatory lesions through D-OCT, corresponding to blood vessel dilation and inflammatory associated hyper-vascularization, may have important clinical consequences in the assessment of HS risk of progression, therapeutic decisions and treatment efficacy monitoring.

Assessment of inter-rater reliability of clinical hidradenitis suppurativa outcome measures using ultrasonography.

BACKGROUND: Hidradenitis suppurativa (HS) staging and severity is typically based upon physical examination findings, which can result in misclassification of severity based on subclinical disease activity and significant variation between healthcare providers. Ultrasonography (US) is an objective tool to help evaluate subclinical disease and to more accurately classify disease severity. AIM: To evaluate inter-rater reliability in HS disease severity assessment using clinical and US techniques. METHODS: In total, 20 subjects underwent clinical evaluation of HS, independently by two physicians, using clinical outcome measures, including Hurley, Sartorius, HS Physician Global Assessment (HS-PGA) and Hidradenitis Suppurativa Clinical Response (HiSCR). US was subsequently performed, and clinical assessments were repeated. Intraclass correlation coefficients (ICC) were obtained to evaluate inter-rater agreement of each outcome measure before and after US. RESULTS: Pre-US to post-US improvement in ICC was seen with the Sartorius, HiSCR nodule and abscess count, and the HiSCR draining fistula count. The scores went from having 'good' rater agreement for Sartorius and HiSCR nodule and abscess count, to 'poor' rater agreement for HiSCR draining fistula count, to 'excellent' rater agreement among these scores. CONCLUSION: US improved inter-rater agreement and should be used in conjunction with physical examination findings to evaluate disease severity to ensure uniform staging of HS.

High inflammation in hidradenitis suppurativa extends to perilesional skin and can be subdivided by lipocalin-2 expression.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease presenting with diverse manifestations ranging from nodules and abscesses to draining tunnels. Whether the underlying inflammation from lesions extends to relatively healthy-appearing adjacent perilesional and distant nonlesional skin has not been systematically evaluated. OBJECTIVE: We sought to characterize lesional, perilesional, and nonlesional skin in patients with HS. METHODS: Skin biopsy samples were collected under ultrasound guidance from patients with active, untreated moderate-to-severe HS. Site-matched control biopsy samples from healthy volunteers were used for comparison. RESULTS: RNA sequencing demonstrated that HS skin clustered separately from healthy control skin, with perilesional and lesion skin clustering together and away from nonlesional skin. Immunohistochemistry analysis identified psoriasiform hyperplasia with keratin 16 positivity in both perilesional and lesional skin, with comparable levels of CD3+, CD11c+, and neutrophil elastase-positive cellular infiltration. There was a marked upregulation of IL-17 signaling in perilesional and lesional skin. HS samples clustered on the basis of expression of lipocalin-2 (LCN2), with samples characterized by high LCN2 expression in the skin exhibiting a differing transcriptomic profile with significantly higher overall inflammation than that of skin characterized by low LCN2 levels. CONCLUSIONS: Perilesional HS skin has a transcriptomic and molecular profile comparable to that of lesional skin. HS can be grouped into 2 distinct subtypes based on molecular levels of LCN2 in the skin, with the LCN2-high subtype exhibiting an overall higher inflammatory burden and an upregulation of targetable cytokines. To our knowledge, this is the first study to characterize a unique HS subtype (and a potential endotype) that may guide future therapeutic targets.

Ultrasound-guided injection of intralesional steroids in acute hidradenitis suppurativa lesions: A prospective study.

The management of hidradenitis suppurativa (HS) flares with intralesional steroids lacks strong scientific evidence but limited data suggest that it may be useful. The objective of this study is to assess the clinical and ultrasound responses of HS flares to ultrasound-guided injections of intralesional triamcinolone (40 mg/ml) with a dilution 1:4 versus 1:2 at 30-day (t1), 60-day (t2), and 90-day (t3) follow-up. We recruited patients with ≤3 acute lesions, unresponsive to topical therapy. At baseline we assessed lesions clinically and by ultra-high frequency ultrasound (48 or 70 MHz) and randomly performed an ultrasound-guided injection of triamcinolone. Assessments were repeated at t1, t2, and t3 follow-up, re-injecting the lesion in the case of no or partial response. We treated 49 lesions: 38.8% showed improvements at t1; 46.9% at t2; 6% at t3; and 8.3% showed no clinical and ultrasound improvements. Long-term follow-up data confirmed a statistically significant reduction in Visual Analogue Scale (VAS)-pain, Dermatology Life Quality Index (DLQI), and HS-Physician Global Assessment (HS-PGA), as well as edema and vascular signals. No adverse effects were reported. Our study suggests that ultrasound-injections with a 1:2 dilution are beneficial for HS flares that do not respond to topical treatment and should be included in the therapeutic algorithm.

Should We Scan Hidradenitis Suppurativa Patients? A Systematic Review of Radiologic Findings.

OBJECTIVE: To bring awareness and close gaps between dermatologists and radiologists about the contribution of imaging techniques for diagnosis, treatment, and follow-up of hidradenitis suppurativa (HS). DATA SOURCES: Investigators searched the PubMed database for articles on HS and radiology techniques. STUDY SELECTION: Databases were searched up to December 2018. The query retrieved 257 publications, of which 103 were unique; of these, 7 were inaccessible. From the remaining 96, 33 were irrelevant (did not discuss HS lesion features). After applying the inclusion criteria, 63 studies were relevant to this study. DATA EXTRACTION: A standardized form was constructed to extract data from eligible studies by two independent authors. DATA SYNTHESIS: Imaging techniques are significant and useful tools in HS management. Imaging should be carried out to evaluate disease severity, subclinical features, treatment success, and intraoperative patient assessment. Providers should consider nonconventional radiology techniques, which are underused in clinical management of HS. Further, dermatology and radiology require a shared terminology of disease features to better understand patient status. CONCLUSIONS: Publications on HS lesion imaging have increased over the years. Imaging techniques have proven useful for determining HS severity and treatment effectiveness, as well as intraoperative patient assessment. These authors strongly recommend the use of these techniques in routine clinical practice for patients with HS.

Ultrasound-guided de-roofing of epithelialised tunnels of hidradenitis suppurativa.

Hidradenitis Suppurativa is a chronic inflammatory disease manifesting in painful nodules, abscesses and malodorous draining tunnels with a pre-disposition to flexural regions of skin. Traditional surgical interventions include excision of clinically visible lesions and in severe cases - excision down to fascia of entire anatomical regions (axilla, groin) and repair with split-thickness grafting or skin substitutes. However, such techniques are plagued by long healing times (up to several months), extensive tissue loss and high recurrence rates given that a large proportion of disease is not clinically visible. Deroofing is a tissue-saving surgical technique, ideal for Hurley Stage 2 disease, which when combined with bedside pre-operative sonography can allow for the accurate identification and removal of occult dermal tunnels whilst minimising the risks of pain, infection, minimising healing times and can be safely conducted in the setting of immunomodulatory therapy.

Sonographic Evaluation of Hidradenitis Suppurativa with Smartphone-Linked Portable Ultrasound.

BACKGROUND: Clinical staging systems for hidradenitis suppurativa (HS) have poor interrater reliability and may underestimate disease activity. Sonographic staging systems may overcome these challenges, but conventional ultrasound (US) machines are expensive and bulky. Portable (p)US may facilitate the integration of sonography into routine practice. OBJECTIVES: To assess the ability of a novel smartphone-linked pUS device to identify key sonographic lesions of HS. METHODS: The charts of 16 patients with HS who were assessed with pUS at the outpatient Dermatology and Wound Care Clinics of a university hospital center were retrospectively reviewed. Clinical and sonographic images of the affected areas were examined. The main outcome measures were the number of patients with identifiable sonographic lesions and the number of patients with subclinical lesions detected by pUS. RESULTS: All 3 key sonographic lesions of HS were identifiable with pUS. Sonographic lesions were identified in 10 patients (62.5%). Subclinical lesions were identified in 2 patients (12.5%); in both cases, this affected management decisions. CONCLUSIONS: We demonstrate the ability of pUS to identify the key sonographic lesions of HS. pUS is a simple and affordable way to integrate HSUS into clinical and research settings, with clear potential benefits to patients.

Real-Time Confocal Imaging for Hidradenitis Suppurativa: Description of Morphological Aspects and Focus on the Role of Follicular Ostia.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease involving the follicular unit. Growing evidence suggests a crucial role of hyperkeratosis, infundibular plugging and perifolliculitis in its pathogenesis. OBJECTIVES: To characterize the microscopic morphology of open comedos using in vivo reflectance confocal microscopy (RCM) and define alterations occurring in HS normal-appearing perilesional skin compared to healthy skin of a control group, discussing therefore microscopic differences. MATERIALS AND METHODS: Twenty patients (11 males, 9 females; aged 19-51 years) affected by HS were recruited. RCM was performed on open comedos of axillary/inguinal regions and on normal-appearing skin areas distant at least 1.5 cm from HS lesions. Ten healthy individuals (6 males, 4 females) were included as control group. RESULTS: RCM aspects of 78 open comedos were explored, observing circular/ovoidal structures disclosing a hyperrefractive amorphous material (72/78, 92.3%) within the infundibular cavity surrounded with a bright (51/78, 65.4%) and regular (52/78, 66.2%) border. Follicular ostia of HS perilesional skin (n = 541) compared to follicular ostia of a control group (n = 321) were characterized by a larger infundibular diameter (183.4 vs. 85.8 µm) and diverged in terms of material collected inside infundibula (44.5 vs. 21%) and keratinization of the border (47.6 vs. 25.5%). CONCLUSION: In vivo characterization of open comedos and the recognition of microscopic subclinical alterations of HS normal-appearing skin, compared to healthy skin, could add further insights into the definition of biological events leading to HS manifestations, including the dysregulated process of keratinization.