Ultrasound Diagnosis and Staging in Pediatric Hidradenitis Suppurativa

Ultrasonography of Facial and Submandibular Hidradenitis Suppurativa and Concomitance with Acne Vulgaris

OBJECTIVES

To describe the ultrasound characteristics of facial and submandibular hidradenitis suppurativa (HS) and detect acne vulgaris (AV) concomitance in these cases.

METHODS

We performed a retrospective study of the ultrasound images of patients with facial HS who had been clinically evaluated by dermatologists. The reported ultrasound diagnostic criteria, severity (mSOS-HS), and activity (US-HAS) staging of HS were used to categorize the patients. The finding of fragments of hair tracts within the key lesions (dilated hair follicles, pseudocysts, fluid collections, and tunnels) was considered a pivotal sign to discriminate HS from AV. Demographic and morphological analysis of the images were considered.

RESULTS

Thirty-three patients met the criteria (78.8% male/21.2% female). Of these, the mSOS- HS scoring was stage I in 51.5%, stage II in 27.3%, and stage III in 21.2%. Dilation of the hair follicles and the presence of pseudocysts, fluid collections, and tunnels were detected in the HS cases; 63.1% of pseudocysts, 62.4% of tunnels, and 46.2% of fluid collections contained fragments of hair tracts. In all HS cases, there was a key lesion(s) with fragments of hair tracts. Four (12.1%) patients showed concomitant facial HS and acne ultrasound lesions. The acne lesions were pseudocysts without inner hair tract fragments in all cases, and the SOS-Acne scoring was stage II for all of them.

CONCLUSION

Facial HS can be detected on ultrasound and shows a morphology similar to that of HS in other corporal regions. In some cases, facial HS could be concomitant with AV. The subclinical ultrasonographic information can support a better management of these cases.

Role of Color Doppler Ultrasound in Cutaneous Inflammatory Conditions

Inflammatory cutaneous diseases can be challenging to diagnose and manage. Nowadays, the anatomical information provided by ultrasound is critical for detecting subclinical alterations and assessing the severity and activity of these conditions. Many of these entities can be clinically observed in dermatology and other specialties, such as rheumatology, plastic surgery, ophthalmology, and otolaryngology, among others. We review the ultrasonographic patterns of the most common inflammatory cutaneous conditions. In several cases, such as hidradenitis suppurativa, acne, and morphea, there are ultrasonographic staging systems of severity or activity that are pivotal in the management of these diseases. The early ultrasonographic diagnosis of these entities implies a proper management of the patients and, therefore, improve their quality of life. Thus, knowledge of the current use of ultrasound in this field seems essential.

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.

The Role of FDG-PET in the Evaluation of Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic skin disorder characterized by nodules, comedones, and sinus tracts that often leave prominent scarring. In recent years, non-invasive imaging techniques have been used to assess the inflammatory activity, vascularization, and treatment response of lesions. Specifically, fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scans may aid in identifying systemic inflammation in patients with HS, improving diagnosis. Inflamed hypermetabolic tissues exhibit a greater uptake of FDG due to increased glucose uptake and vascularity. A systematic review was conducted to summarize the utility of nuclear imaging techniques in the diagnosis and treatment follow-up of HS. PubMed, Scopus, and ScienceDirect databases were utilized for relevant articles discussing the utility of PET scans in managing HS. A total of 51 citations were identified in the initial search. Following the review of titles, abstracts, and duplicates, 43 articles were excluded, leaving a total of eight articles for analysis. Data were extracted from each article, encompassing the number of patients, imaging techniques employed, and final results. An analysis of the data demonstrated that FDG-PET showed evidence of identifying subclinical lesions of the disease, improving the visualization of HS, and providing an objective method of assessing severity.

Clinical and Ultrasonographic Characterization of Hidradenitis Suppurativa in Female Patients: Impact of Early Recognition of the Disease

Hidradenitis suppurativa (HS) is considered a post-pubertal disease; however, earlier onset is not infrequent. The burden of HS on the female population is very relevant, and early identification might reduce the quality of life impairment and improve the therapeutic approach. In this study, we investigated clinical biomarkers of HS that could impact the management of patients affected by HS. Female patients affected by stable HS were prospectively included in this study. Anamnestic data, clinical and ultrasonographic features were collected and analyzed. Overall, 53 patients were included in this study. The median age of onset was 19 (IQR: 14-25). Early onset was reported by 22/53 patients (median age of onset: 14; IQR: 11-16). Four patients had pre-menstruation occurrence. Early-onset patients had an earlier first-menstrual-cycle age and more frequent genital localization of HS, and were more often treated with biologics. Patients with early-onset-HS and genital localization had more severe disease with a higher number of areas affected, Hurley, and IHS4 scores. Genital involvement might be prevalent in patients with early-onset HS, leading to a worse impact on the global severity of the disease and tailored treatment protocols, including multidisciplinary approaches, in order to improve the early recognition of hidden lesions.

Key Points to Select a Device for Dermatologic Ultrasound

What points to consider when selecting a device for practicing dermatologic ultrasound is an excellent question. After we met the requisites published in the guidelines for practicing dermatologic ultrasound, it is necessary to consider the main objective of the use because it is not the same to be focused mostly on the avoidance of the puncture of important facial vessels such as the case of injectors of cosmetic fillers in comparison to the use of operators that need to deal with the diagnosis and monitoring of a wide range of dermatologic pathologies. Currently, a broad variety of ultrasound devices meets the minimum requirements for practicing these examinations in the market. Thus, small, portable, and high-end devices may present advantages and limitations that must be balanced according to the primary purposes and the budget. Moreover, the shape and footprint of the probes can make difficult or facilitate a dermatologic procedure. Other points to consider are the type of storage and the need for technical service. In summary, there are key points that we need to consider when we select a dermatologic ultrasound device in dermatology or aesthetics.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part I: Extraarticular Pathologies

The first part of the guidelines and recommendations for musculoskeletal ultrasound, produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), provides information about the use of musculoskeletal ultrasound for assessing extraarticular structures (muscles, tendons, entheses, ligaments, bones, bursae, fasciae, nerves, skin, subcutaneous tissues, and nails) and their pathologies. Clinical applications, practical points, limitations, and artifacts are described and discussed for every structure. After an extensive literature review, the recommendations have been developed according to the Oxford Centre for Evidence-based Medicine and GRADE criteria and the consensus level was established through a Delphi process. The document is intended to guide clinical users in their daily practice.

Practical applications of ultrasound in dermatology

Ultrasound has evolved in dermatology from an experimental phase to a daily practice imaging technique. Its several advantages include its safety, good balance between penetration and resolution, high definition, and the detection of blood flow in real time. Its applications are growing and include the support of the diagnosis and extent in all axes, including depth, vascularity patterns, staging, and follow up of multiple cutaneous diseases-benign cutaneous tumors, vascular anomalies, nail lesions, skin cancer, inflammatory cutaneous diseases, and aesthetics complications.

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.

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. Ultrasound (US) is an objective tool to help evaluate subclinical disease and more accurately classify severity of disease. The objective of this study was to evaluate inter-rater reliability in HS disease severity assessment using clinical and US techniques.

METHODS

Twenty subjects underwent clinical evaluation of HS using clinical outcome measures including Hurley, Sartorius, HS Physician Global Assessment (HS-PGA), and Hidradenitis Suppurativa Clinical Response (HiSCR) independently by two physicians. US was subsequently performed, and clinical assessments were repeated. Intra-class correlation coefficients (ICC) were obtained to evaluate inter-rater agreement of each outcome measure before and after US.

RESULTS

Pre- to post-US improvement in ICC was seen with the Sartorius, HiSCR nodule and abscess count, and HiSCR draining fistula count. The scores went from having "good" rater agreement for Sartorius and HiSCR nodule and abscess count and "poor" rater agreement for HiSCR draining fistula count to "excellent" rater agreement amongst these scores.

CONCLUSIONS

US improved inter-rater agreement and should be used in conjunction with physical examination findings to evaluate disease severity to ensure uniform staging.

Differences Between Children and Adults With Hidradenitis Suppurativa

Importance

Up to 50% of patients may have hidradenitis suppurativa (HS) onset between age 10 and 21 years. To our knowledge, little is known about how adolescents with HS utilize health care during their journey to receiving a diagnosis.

Objective

To assess the clinical characteristics and health care utilization patterns of pediatric vs adult patients with HS.

Design, Setting, and Participants

This retrospective cohort study included adult and pediatric patients with HS claims from the MarketScan medical claims database during the study period, January 1, 2012, to December 31, 2016. The data were analyzed between March 1 and March 31, 2021.

Exposures

Clinical characteristics and health care utilization patterns of pediatric vs adult patients with HS.

Main Outcomes and Measures

Health care utilization patterns were examined and included concurrent diagnoses, outpatient care by discipline, and emergency/urgent care and inpatient claims.

Results

This study included 8727 members, comprising 1094 pediatric (155 male [14.2%] and 939 female patients [85.8%]; mean [SD] age, 14.3 [2.47] years) and 7633 adult patients (1748 men [22.9%] and 5885 women [77.1%]; mean [SD] age, 37.2 [12.99] years). Pediatric patients were likely to see pediatricians, dermatologists, emergency department (ED) staff, and family physicians before diagnosis and commonly received diagnoses of folliculitis and comedones. Pediatric patients with HS had high rates of comorbid skin and general medical conditions, including acne vulgaris (558 [51.0%]), acne conglobata (503 [45.9%]), obesity (369 [33.7%]), and anxiety disorders (367 [33.6%]). A higher percentage of pediatric than adult patients had HS-specific claims for services rendered by emergency and urgent care physicians (35.6% vs 28.2%; P < .001; and 18.1% vs 13.4%; P < .001; respectively). However, adult patients were more likely to have inpatient stays (2.38% vs 4.22%; P = .002). Pediatric patients had 2.24 ED claims per person, while adults had 3.5 claims per person. The mean cost per ED claim was similar between groups ($413.27 vs $682.54; P = .18). The largest component of the total 5-year disease-specific cost was the cost of inpatient visits for pediatric and adult patients with HS.

Conclusions and Relevance

This cohort study suggests that pediatric patients utilize high-cost ED care when HS can often be treated as an outpatient. These data suggest that there are opportunities to improve recognition of HS in pediatric patients by nondermatologists and dermatologists.

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.

High-frequency ultrasound in clinical dermatology: a review

Background

Ultrasound was first introduced in clinical dermatology in 1979. Since that time, ultrasound technology has continued to develop along with its popularity and utility.

Main text summary

Today, high-frequency ultrasound (HFUS), or ultrasound using a frequency of at least 10 megahertz (MHz), allows for high-resolution imaging of the skin from the stratum corneum to the deep fascia. This non-invasive and easy-to-interpret tool allows physicians to assess skin findings in real-time, enabling enhanced diagnostic, management, and surgical capabilities. In this review, we discuss how HFUS fits into the landscape of skin imaging. We provide a brief history of its introduction to dermatology, explain key principles of ultrasonography, and review its use in characterizing normal skin, common neoplasms of the skin, dermatologic diseases and cosmetic dermatology.

Conclusion

As frequency advancements in ultrasonography continue, the broad applications of this imaging modality will continue to grow. HFUS is a fast, safe and readily available tool that can aid in diagnosing, monitoring and treating dermatologic conditions by providing more objective assessment measures.

Doppler ultrasound-based noninvasive biomarkers in hidradenitis suppurativa: evaluation of analytical and clinical validity

BACKGROUND

There is a need for valid and reliable biomarkers in hidradenitis suppurativa (HS) for diagnosis and disease activity monitoring. Imaging-based biomarkers have the potential to fulfil this unmet need but no evaluation of analytical or clinical validity has yet been undertaken.

OBJECTIVES

To evaluate the analytical and clinical validity of sonographic epidermal thickness, Doppler ultrasound and dermal tunnel diameter in patients with HS.

METHODS

Twenty-two participants with HS were recruited and underwent a total of 65 matched ultrasound and skin biopsies of lesional, perilesional and unaffected tissue. Ultrasound measurements were performed in triplicate with mean values used. Skin biopsies underwent immunohistochemistry as per previously published methods. Analytical validity was assessed in individual ultrasound-biopsy pairs (n = 65) by comparisons of sonographic variables with histological correlates. Clinical validity was assessed in individual patients (n = 22) by comparing measures of overall disease activity with sonographic outcomes.

RESULTS

Epidermal thickness, dermal tunnel diameter and power Doppler intensity were assessed. Sonographic epidermal thickness and dermal tunnel diameter have high analytical validity with corresponding histological measurements. Power Doppler intensity demonstrated high correlation with dermal CD3⁺ and CD11c⁺ cell counts but not neutrophil elastase-positive cells. Power Doppler ultrasound has significant correlation with pain scores, abscess and nodule count, International HS Severity Scoring System score and number of draining tunnels.

CONCLUSIONS

Sonographic epidermal thickness and dermal tunnel diameter have acceptable levels of analytical validity in the assessment of HS lesions. Power Doppler intensity demonstrates acceptable clinical and analytical validity, suggesting it is a valid imaging-based biomarker in HS.

Seventy-MHz Ultrasound Detection of Early Signs Linked to the Severity, Patterns of Keratin Fragmentation, and Mechanisms of Generation of Collections and Tunnels in Hidradenitis Suppurativa

OBJECTIVES

To test the capability of 70-MHz ultrasound for detecting initial ultrasound signs of hidradenitis suppurativa (HS) linked to severity.

METHODS

A cross-sectional study of the ultrasound images of patients with HS was conducted and compared with a healthy control group. Detection and identification of early subclinical ultrasound signs in the lesional and perilesional areas of the HS cases in comparison with the control group were performed. Statistical analyses included mean, dispersion measures, the Kruskal-Wallis test, and bivariate and multivariate ordered logistic regression studies. Significance was assessed at P < .05.

RESULTS

A total of 139 patients with HS met the criteria and showed abnormalities of the hair follicles such as a curved shape, ballooning, and protrusion into pseudocysts, collections, or tunnels (donor of keratin sign). Significant increases in the sizes of the hair follicles and hair shafts were found in HS cases. The following ultrasound signs were significantly linked to severity: a connecting band between the base of adjacent hair follicles (bridge sign), a fragment of the hair shaft extruding through a dilated hair follicle (sword sign), and retained cylindrical fragments of keratin in the dermis. Two patterns of fragmentation of the keratin were detected: multifragment and cylindrical.

CONCLUSIONS

Ultrasound can detect early HS signs that are significantly linked to severity and 2 types of fragmentation of the keratin, which could support the generation and perpetuation of the fluid collections and tunnels. These ultrasound signs can help prompt diagnosis and management, the development and testing of medications, and the measure of treatment outcomes in HS.

Cutaneous ultrasound and its utility in pediatric dermatology. Part I: Lumps, bumps, and inflammatory conditions

High-frequency ultrasonography represents a promising tool for pediatric dermatologists. It is a non-invasive diagnostic technique that is particularly appealing when working with children. It can be easily performed at the patient's bedside, avoiding diagnostic delays, sedation, or multiple visits. It represents a useful adjunct to clinical examination and can enhance our understanding of cutaneous diseases. Patient cooperation and limited training and experience are the main challenges for cutaneous ultrasonography in pediatric dermatology. This review describes cutaneous ultrasonography and the nuances of its use in the pediatric setting, followed by the ultrasonographic findings of cutaneous lumps, bumps, and inflammatory dermatoses commonly encountered in pediatric patients.

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.

Current and future treatment of hidradenitis suppurativa

This scholarly review on the current and future treatment of hidradenitis suppurativa (HS) focuses on medical and surgical treatment options, while novel pipeline drugs are also discussed. Treatment goals are to limit the incidence and duration of flares, reducing inflammation and suppuration, achieving local cure after surgery and, most importantly, to improve the quality of life of patients with HS. The type of medication and/or surgery should be chosen based on the stage of the disease and the degree of inflammation. However, the lack of a simple scoring system and the lack of clear surgical outcome definitions hamper the interpretation of treatment efficacy and the comparison between different treatment strategies. The therapeutic pipeline for HS is gradually expanding, and will probably lead to a broader panel of more effective therapeutic options.

Ultrasound and Infrared-Based Imaging Modalities for Diagnosis and Management of Cutaneous Diseases

Non-invasive bedside imaging tools are becoming more prevalent for assessing cutaneous lesions. Ultrasound used at specific frequencies allows us to assess margins of lesions to minimize the extent of the biopsy that is performed and improve cosmetic outcomes. Vascularity, seen on Doppler ultrasound and contrast-enhanced ultrasound, and stiffness, assessed on tissue elastography, can help differentiate between benign and malignant lesions for clinicians to be more judicious in deciding whether to biopsy. Moreover, research has shown the efficacy in using ultrasound in monitoring flares of hidradenitis suppurativa, a disease affecting apocrine gland-rich areas of the body, for which the current gold standard involves examining and scoring inflammatory lesions with the naked eye. Infrared-based modalities have also been on the uptrend to aid in clinical decision-making regarding suspiciousness of lesions. Reflectance confocal microscopy has lateral resolution that is comparable to histopathology and it has been shown to be an appropriate adjunctive tool to dermoscopy, specifically when evaluating melanomas. Optical coherence tomography has utility in determining lesion thickness because of its depth penetration, and spectrophotometric intracutaneous analysis is becoming more popular as a tool that can be used by general practitioners to know when to refer to dermatology regarding worrisome pigmented lesions. Strides have been made to incorporate electrical impedance spectroscopy alongside dermoscopy in decision-making regarding excision, although the evidence for its use in the clincial setting remains inconclusive. This paper reviews the efficacy and drawbacks of these techniques in the field of dermatology and suggests future directions.

Current applications of high-frequency ultrasonography in dermatology

The era of ultrasounds in dermatology started in 1979, when pioneering use of 15 MHz by Alexander and Miller in measuring the skin thickness was introduced. Since then, some new applications of high-frequency ultrasonography (HF-USG) have emerged providing the clinicians with an extra hand in their everyday practice. The main advantages of HF-USG include the possibility of real-time imaging, measurements of morphological and physiological aspects of the skin, safety associated with the use of non-ionizing media as well as the lack of contraindications to its performance. Currently the main clinical use of HF-USG in dermatology regards preoperative assessment of the depth of invasion in melanomas and basal cell carcinomas. The ultrasound image analysis allows noninvasive follow-up of inflammatory skin diseases, like atopic dermatitis, psoriasis and may be used for monitoring effectiveness of therapy in skin lymphomas and sclerotic skin diseases.