Update on hidradenitis suppurativa: connecting the tracts

Uncovering the burden of hidradenitis suppurativa misdiagnosis and underdiagnosis: a machine learning approach

Hidradenitis suppurativa (HS) is a chronic inflammatory follicular skin condition that is associated with significant psychosocial and economic burden and a diminished quality of life and work productivity. Accurate diagnosis of HS is challenging due to its unknown etiology, which can lead to underdiagnosis or misdiagnosis that results in increased patient and healthcare system burden. We applied machine learning (ML) to a medical and pharmacy claims database using data from 2000 through 2018 to develop a novel model to better understand HS underdiagnosis on a healthcare system level. The primary results demonstrated that high-performing models for predicting HS diagnosis can be constructed using claims data, with an area under the curve (AUC) of 81%-82% observed among the top-performing models. The results of the models developed in this study could be input into the development of an impact of inaction model that determines the cost implications of HS diagnosis and treatment delay to the healthcare system.

Epigenetic switch reshapes epithelial progenitor cell signatures and drives inflammatory pathogenesis in hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a complex inflammatory skin disease with undefined mechanistic underpinnings. Here, we investigated HS epithelial cells and demonstrated that HS basal progenitors modulate their lineage restriction and give rise to pathogenic keratinocyte clones, resulting in epidermal hyperproliferation and dysregulated inflammation in HS. When comparing to healthy epithelial stem/progenitor cells, in HS, we identified changes in gene signatures that revolve around the mitotic cell cycle, DNA damage response and repair, as well as cell-cell adhesion and chromatin remodeling. By reconstructing cell differentiation trajectory and CellChat modeling, we identified a keratinocyte population specific to HS. This population is marked by S100A7/8/9 and KRT6 family members, triggering IL1, IL10, and complement inflammatory cascades. These signals, along with HS-specific proinflammatory cytokines and chemokines, contribute to the recruitment of certain immune cells during the disease progression. Furthermore, we revealed a previously uncharacterized role of S100A8 in regulating the local chromatin environment of target loci in HS keratinocytes. Through the integration of genomic and epigenomic datasets, we identified genome-wide chromatin rewiring alongside the switch of transcription factors (TFs), which mediated HS transcriptional profiles. Importantly, we identified numerous clinically relevant inflammatory enhancers and their coordinated TFs in HS basal CD49fhigh cells. The disruption of the S100A enhancer using the CRISPR/Cas9-mediated approach or the pharmacological inhibition of the interferon regulatory transcription factor 3 (IRF3) efficiently reduced the production of HS-associated inflammatory regulators. Our study not only uncovers the plasticity of epidermal progenitor cells in HS but also elucidates the epigenetic mechanisms underlying HS pathogenesis.

The efficacy and safety of endo-radiofrequency for the treatment of hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic and recurrent disease of the axilla and groin with inflammatory lesions. There is no definitive medication or intervention to cure the disease. Radiofrequency (RF) is a modality to destroy the lesions by transferring heat into the skin. To date, few studies have been conducted to evaluate the efficacy and safety of RF at HS.

METHODS

This 9-month, prospective, nonrandomized, and single-blinded study is a clinical trial conducted in 10 patients with refractory HS. In all patients, the initial grade of HS was evaluated. The procedure involved treating HS of the axilla with a endo-RF wave device. Post-treatment evaluation included: determination of the severity of the disease by a blinded dermatologist, the degree of patient satisfaction, tolerability in each patient, and complications of the procedure. We also evaluate the recurrence of the disease during a 6-month follow-up.

RESULTS

The satisfaction level after the intervention among under-studied cases was excellent and good in six of cases. There was a significant difference in comparing the grading score of patients before and 3 months after receiving RF (P-value: 0.01). Regarding tolerability, eight of the patients could tolerate it. We had no complication after the intervention and four cases had not recurrence during a 6-month follow-up.

CONCLUSION

Endo-RF is an effective and safe modality for treating HS however to prevent the recurrence, periodic therapy sessions are needed.

Clinical-Epidemiological Characteristics of Hidradenitis Suppurativa: A Retrospective Cohort Study from a Tertiary Care Centre in Northern Israel

BACKGROUND

Hidradenitis suppurativa (HS) is characterised by inflamed lesions that typically appear in apocrine-rich flexural areas. Although studies have reported clinical and epidemiological data from western countries, data from the Middle East are scarce. The aim of this study is to characterise the differences in the clinical characteristics of patients with HS of Arab and Jewish ancestry and review the clinical characteristics, the course of the disease, the comorbidities, and the response to treatment.

METHODS

This is a retrospective study. We collected clinical and demographic data from patient files between 2015-2018 at the Rambam Healthcare Campus dermatology clinic-a tertiary hospital located in the north of Israel. Our results were compared to those of a previously published Israeli control group registered in Clalit Health Services.

RESULTS

Of the 164 patients with HS, 96 (58.5%) were men and 68 (41.5%) were women. The average age at diagnosis was 27.5 years and the average latency between the onset and diagnosis of the disease was 4 years. We found a higher adjusted prevalence of HS in Arab patients (56%) than in their Jewish counterparts (44%). Gender, smoking, and obesity, as well as axilla and buttock lesions, were risk factors for severe HS, with no differences between ethnicities. No differences were documented in comorbidities and in response to adalimumab, with a high overall response rate of 83%.

CONCLUSIONS

Our findings revealed differences between Arab and Jewish patients with HS in terms of incidence and gender predominance, while no differences were documented in comorbidities and response to adalimumab.

Can hidradenitis suppurativa patients classify their lesions by means of a digital lesion identification scheme?

BACKGROUND AND OBJECTIVES

Hidradenitis suppurativa (HS) differs widely with respect to its clinical presentation. Literature imposes different phenotypes potentially implying different treatment modalities. The aim of this study is to develop a validated scheme that enables HS patients to identify their own lesion types.

PATIENTS AND METHODS

The developed schemes for physicians and patients were implemented in a specific software. Upon patient consent, the physician used the software to document the lesions identified. Patients subsequently logged into the patient-version of the software from the convenience of their home and selected the lesions they identified on themselves. Afterwards the correlation between professionals and patients was tested.

RESULTS

For seven lesion types, correlation coefficients were statistically significant. A large/strong correlation between patients and physicians was found for the draining fistulas (0.59) and double-ended comedones (0.50). For five other lesion types, correlation was medium/moderate, namely the inflammatory nodule (0.37), abscess (0.30), accordion like-/ bridged scar (0.45), epidermal cyst (0.33) and pilonidal sinus (0.39).

CONCLUSIONS

HS-patients demonstrate high willingness to share their experiences and data. Therefore, a self-assessment scheme, as the developed LISAI, can be a valuable tool to enrich patient surveys with the identification of lesion types, for instance as a basis for phenotyping.

Effects of NCSTN Mutation on Hair Follicle Components in Mice

BACKGROUND AND OBJECTIVES

Hidradenitis suppurativa (HS)/acne inversa is an intractable skin disease that is characterized by destructive lesions - primarily on the flexural areas. Although its etiology is unknown, genetics is considered to be a factor of its pathology - mutations in γ-secretase genes have been identified in certain familial HS patients, and follicular occlusion is widely accepted as the primary cause of HS. But, no relationship between these mutations and the components of hair follicles has been reported. Thus, we examined changes in these components in mice with a mutation in NCSTN (a γ-secretase gene).

METHODS

We generated C57BL/6 mice with an NCSTN mutation and examined their expression of hair cortex cytokeratin and trichohyalin by Western blot and immunohistochemistry, in addition to nicastrin, the product of NCSTN, and NICD compared with wild-type mice. The structure of hair follicles was analyzed by hematoxylin-eosin staining and transmission electron microscopy.

RESULTS

In mice with an NCSTN mutation, HS-like skin lesions appeared after age 6 months, the pathological manifestations of which were consistent with the features of human HS. The structure of hair follicles was abnormal in mice with an NCSTN mutation versus wild-type mice, and hair cortex cytokeratin, trichohyalin, nicastrin, and NICD were downregulated in these mice.

CONCLUSIONS

This NCSTN mutant mouse model could be an improved model to study early lesion development aspects of human HS pathogenesis and could perhaps be a better alternative for evaluating early-acting and preventive therapeutics for HS experimentally before clinical trials in HS patients. NCSTN mutations disrupt the development of hair follicles, leading to abnormal hair follicle structures, perhaps resulting in the onset of HS.

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.

Epithelialized tunnels are a source of inflammation in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic, painful, and burdensome inflammatory disease manifesting in nodules and abscesses, with progression to chronically draining tunnels in later-stage disease.

OBJECTIVE

We sought to determine whether HS tunnels are immunologically active participants in disease activity.

METHODS

Skin biopsy specimens were obtained by using ultrasound guidance in untreated patients with HS and those enrolled in an open-label study of brodalumab (ClinicalTrials.gov identifier NCT03960268) for patients with moderate-to-severe HS.

RESULTS

Immunohistochemistry of HS biopsy specimens demonstrated that the epithelialized HS tunnels recapitulate the psoriasiform epidermal hyperplasia morphology of the overlying epidermis, displaying molecular inflammation, including S100A7 (psoriasin) positivity, as well as features of epidermal skin, including loricrin, filaggrin, lipocalin-2, and Melan-A positive cells. Tunnels were associated with increased infiltration of T cells, dendritic cells, and neutrophils; formation of neutrophil extracellular traps, and increased expression of psoriasiform proinflammatory cytokines. Unsupervised hierarchical clustering demonstrated a separation of HS samples based on the presence or absence of tunnels. Tunnels isolated by microdissection had higher levels of epithelium-derived inflammatory cytokines compared with the overlying epidermis and healthy controls. Clinically, the size and draining of the tunnels were decreased with treatment with the IL-17RA antagonist brodalumab.

CONCLUSION

These data suggest that tunnels are a source of inflammation in HS.

Combining Deroofing with LAight® Therapy for Long-Term Disease Control of Hurley Stage II Hidradenitis Suppurativa: Case Report

There is an increasing consensus that the treatment of Hidradenitis suppurativa (HS) significantly varies with the degree of inflammation and that treatment according to guidelines is not always successful. Here, we report the case of a 31-year-old male with widespread, highly inflammatory Hurley Stage II HS in multiple locations who failed to respond to any kind of established medical treatment, including biologics. As an alternative approach, Ustekinumab was maintained, and additionally the patient was treated with LAight therapy, a combination of intense pulsed light and radiofrequency. After 10 sessions, deroofing of multiple lesions was performed in a two-step process. After a few weeks of healing time accompanied by specialized wound experts, the patient continued with LAight therapy to control and prevent recurrence. This case shows that the combination of LAight therapy and deroofing is a promising treatment plan for the long-term symptom control of mild and moderate HS.

Combined treatment of hidradenitis suppurativa with intense pulsed light (IPL) and radiofrequency (RF)

BACKGROUND

Hidradenitis suppurativa is a chronic inflammatory disease with high burden. Treatment options are often unsatisfactory. We assessed the effect of a combination therapy of intense pulsed light (IPL) and radiofrequency (RF).

METHODS

The explorative study included 47 patients and was performed as a prospective, monocentric, randomized, three-arm parallel-group design trial with a prior 12 weeks observation period. Treatment arms were IPL and RF monotherapies or IPL + RF combination therapy. After 12 weeks, all patients received IPL + RF for additional 12 weeks (cross-over). Primary endpoint was the change in active lesion numbers, secondary endpoint the change in Dermatology Quality of Life Index (DLQI).

RESULTS

After 12 weeks, active lesion counts of the IPL + RF group decreased more than in the IPL group (p = .044); the decrease in DLQI was significantly higher in the IPL + RF and RF groups compared to IPL. Prolonged 24-week treatment with IPL + RF obtained better results as 12 weeks. Overall, disease burden after 24 weeks of treatment compared to disease fluctuation during the observation period was significantly lower (change in active lesions -3.6, p = .001; in DLQI -5.2, p = .003).

CONCLUSIONS

IPL + RF treatment appears to represent a promising therapeutic option that leads to reduction of disease activity without severe side effects.

Diet in hidradenitis suppurativa: a review of published and lay literature

Hidradenitis suppurativa (HS) is a chronic, recurring, inflammatory skin disorder resulting in skin abscesses and sinus tracts of the skin folds. Hidradenitis suppurativa remains a disease with limited treatment options. Management of disease activity with dietary modification has been of considerable interest to the HS patient community. Limited evidence exists to support dietary changes for treatment of HS. Strategies such as eliminating dairy products, limiting simple carbohydrate and sugar intake, and avoiding nightshades (Solanaceae) and foods containing brewer's yeast have been reported to be helpful in some patients. Several supplements have also been touted as beneficial. Herein, we review the existing dietary recommendations in both peer-reviewed and lay literature in an attempt to consolidate and evaluate existing information, while stimulating further inquiry into the role of diet in HS. Although dietary modifications are often of considerable interest to HS patients, there is a paucity of data regarding diet as it relates to HS. It is unclear whether diet may prove to be of value in limiting the severity of HS. Further research is needed to determine the potential benefits of these dietary changes.

Consensus on the treatment of hidradenitis suppurativa - Brazilian Society of Dermatology

Hidradenitis suppurativa is a chronic immune mediated disease of universal distribution that causes great damage to the quality of life of the affected individual, whose prevalence is estimated at 0.41% in the Brazilian population. The objective of this work was update on physiopathogenesis, diagnosis and classification of hidradenitis suppurativa and to establish therapeutic recommendations in the Brazilian reality. It was organized as a work group composed of eight dermatologists from several institutions of the country with experience in the treatment of hidradenitis suppurativa and carried out review on the topic. Recommendations were elaborated and voted by modified Delphi system and statistical analysis of the results was performed. The Brazilian consensus on the clinical approach of hidradenitis suppurativa had the support of the Brazilian Society of Dermatology.

Topical, systemic and biologic therapies in hidradenitis suppurativa: pathogenic insights by examining therapeutic mechanisms

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the skin, manifesting in chronic, recurrent painful pustules, nodules, boils and purulent draining abscesses. Our current understanding of the pathogenesis of the disease is incomplete. This review aims to identify available treatment options in HS and discuss the pharmacological mechanisms through which such agents function. Identifying common pathways may inform our understanding of the pathogenesis of HS as well as identify future therapeutic targets. The pharmacological mechanisms implicated in topical therapies, antibiotic, hormonal, systemic immunomodulatory and biologic therapies for HS are discussed. Significant differences exist between agents and implicated pathways in therapy for mild and severe disease. This is an expression of the possible dichotomy in inflammatory pathways (and treatment responses) in HS. Studies involving monoclonal antibodies provide the greatest insight into what these specific mechanisms may be. Their variable levels of clinical efficacy compared with placebo bolsters the suggestion that differential inflammatory pathways may be involved in different presentations and severity of disease. Nuclear factor kappa B (NF-κB), tumor necrosis factor (TNF)-α and other innate immune mechanisms are strongly represented in treatments which are effective in mild to moderate disease in the absence of scarring or draining fistulae, however complex feed-forward mechanisms in severe disease respond to interleukin (IL)-1 inhibition but are less likely to respond to innate immune inhibition (through NF-κB or TNF-α) alone. It is unclear whether IL-17 inhibition will parallel TNF-α or IL-1 inhibition in effect, however it is plausible that small molecule targets (Janus kinase1 and phosphodiesterase 4) may provide effective new strategies for treatment of HS.

The Comorbidity Burden of Hidradenitis Suppurativa in the United States: A Claims Data Analysis

INTRODUCTION

Prior studies have reported that hidradenitis suppurativa (HS) is accompanied by a myriad of physical and mental conditions. However, given the small sample sizes and the limited number of pre-selected comorbidities, these studies do not provide a complete picture of the comorbidity burden of HS in the USA. Moreover, the relationship between HS severity and comorbidity burden has yet to be characterized. Using a large US claims database, we estimated the comorbidity burden associated with HS, stratified by disease severity.

METHODS

A retrospective matched cohort design was used. Patients with HS were classified into two severity cohorts (milder and more severe) using an empirical algorithm based on treatments received. The comorbidity burden was compared between each HS cohort and their matched HS-free cohort, and between patients with milder vs. those with more severe forms of HS.

RESULTS

Several physical and mental comorbidities were found to be more prevalent in both cohorts of patients with milder and more severe forms of HS than in their matched HS-free cohorts. The comorbidity burden also increased greatly as the disease progressed to more severe forms.

CONCLUSIONS

The results of this study highlight the complexity of the comorbidity burden of HS patients and the need for a multidisciplinary approach to optimize the management of HS and its numerous associated comorbidities.

FUNDING

AbbVie, Inc.

Pain, Psychological Comorbidities, Disability, and Impaired Quality of Life in Hidradenitis Suppurativa [corrected]

PURPOSE OF REVIEW

Hidradenitis suppurativa (HS) is a chronic, painful dermatologic disease characterized by recurrent inflammatory nodules and abscesses of intertriginous areas such as the axilla and groin. People with HS suffer from greater pain and associated psychological comorbidities, including depression, anxiety, disability, and impairments in quality of life (QoL), compared to those with other dermatologic conditions. Our review focuses on the occurrence of pain and these relationships.

RECENT FINDINGS

The existing literature indicates that acute and chronic pain, depression, anxiety, and disability all contribute to poor quality of life in individuals with HS. Despite the central role of pain and distress in the presentation of HS, few studies have empirically evaluated the impact of pain and gaps remain in the existing psychosocial literature. There are no formal guidelines for treating HS-specific pain or psychological comorbidities. The results of this review show a clear and pressing need to develop treatment recommendations and effective interventions for addressing acute and chronic pain, psychological comorbidities, disability, and impaired quality of life among people with HS. This review outlines a multidisciplinary approach to treating and managing pain and psychological comorbidities.

Hidradenitis suppurativa: an update on connecting the tracts

Hidradenitis suppurativa (HS) is a devastating disease involving abscesses, sinus tracts, and inflammation classically affecting the axilla, groin, and/or anogenital region. Although the disease pathogenesis is not fully understood, recent advances suggest that HS pathology runs much deeper than the cutaneous manifestations. It is now believed that HS is a systemic inflammatory disease that gives rise to the characteristic cutaneous manifestations. This disease is problematic for both patients and physicians to manage because of a variety of diagnostic and management difficulties. This article seeks to provide updates on the current understanding of HS to increase awareness and improve management.

Medical and Surgical Treatment of Hidradenitis Suppurativa: A Review

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease presenting with painful nodules, abscesses, sinus tracts, and scarring primarily affecting apocrine gland-rich intertriginous areas. HS prevalence ranges from 0.05 to 1%. The central pathogenic event in HS is believed to be the occlusion of the upper part of the folliculopilosebaceous unit, leading to the rupture of the sebofollicular canal with the consequent development of perifollicular lymphohistiocytic inflammation. The HS treatment choices are influenced by disease severity and its individual subjective impact, involving both medical and surgical interventions. However, given the chronic nature of HS, its destructive impact on social, working, and daily life of patients, its management is often frustrating for both the patient and physician. Hence, prompt and effective management strategies are urgently needed and a multidisciplinary approach is advocated. Therefore, in this article, we highlighted the main features of HS (clinical aspects, epidemiology, pathogenesis, diagnostic criteria, classifications, comorbidities, and treatments), so that awareness of this disease might be heightened in primary care physicians and surgeons, who may be the first health care providers to see patients with this disease owing to its characteristic clinical presentation (inflammatory nodules, abscesses, sinus tract, etc.).

Photodynamic therapy with intralesional methylene blue and a 635 nm light-emitting diode lamp in hidradenitis suppurativa: a retrospective follow-up study in 7 patients and a review of the literature

Hidradenitis suppurativa is a chronic inflammatory skin disease which has an estimated prevalence of 1%. It is characterized by the formation of recurrent painful suppurative nodules and abscesses in the flexural areas of the body. It is believed that its pathogenesis involves an aberrant, genetically-determined activation of innate immunity against the bacterial commensal flora of intertriginous areas. It has been found that the formation of antibiotic-resistant bacterial biofilms is a common finding in hidradenitis lesions. Photodynamic therapy with different compounds and light sources has demonstrated its efficacy in a number of infectious diseases such as nail mycosis and chronic periodontitis. We retrospectively report our experience in the treatment of hidradenitis with photodynamic therapy using intralesional methylene blue and a 635 nm light-emitting diode lamp in 7 patients. Two patients received one session whereas 5 patients received two sessions. At one month follow-up good response was achieved in 6 patients. After 6 months, 5 patients (71%) maintained remission of the disease in the treated area. In view of the results and literature review, we regard methylene blue as an ideal photosensitizer for photodynamic therapy in this disease.

A Report of Two Patients with Darier Disease and Hidradenitis Suppurativa

We report two unique cases of patients with Darier disease and hidradenitis suppurativa. Although it is unknown whether there is a connection between the two diseases, it is possible that an interaction between sarcoendoplasmic reticulum calcium transport ATPase and Notch homolog 1, translocation-associated (Drosophila) caused both diseases in these individuals.

Bacteriology of hidradenitis suppurativa/acne inversa: A review

Given that follicular papules and pustules, as well as nodules and abscesses, are the clinical hallmarks of hidradenitis suppurativa (HS), an infectious, bacterial pathway has been suspected in the pathogenesis of this chronic, inflammatory condition. Elucidating the behavior and role of bacterial species in HS and their interaction with cutaneous innate immunity will provide more insight into the pathophysiology of this condition. This review of prospective investigations suggests a synergistic relationship between impaired innate immunity and microbial factors in the etiology of HS.

Acne inversa complicated by Actinomyces neuii

INTRODUCTION

Acne inversa (AI) is a chronic and recurrent inflammatory skin disease. It occurs in intertriginous areas of the skin and causes pain, drainage, malodor and scar formation. While supposedly caused by an autoimmune reaction, bacterial superinfection is a secondary event in the disease process.

METHODS

A unique case of a 43-year-old male patient suffering from a recurring AI lesion in the left axilla was retrospectively analysed.

RESULTS

A swab revealed Actinomyces neuii as the only agent growing in the lesion. The patient was then treated with Amoxicillin/Clavulanic Acid 3 × 1 g until he was cleared for surgical excision. The intraoperative swab was negative for A. neuii. Antibiotics were prescribed for another 4 weeks and the patient has remained relapse free for more than 12 months now.

CONCLUSION

Primary cutaneous Actinomycosis is a rare entity and the combination of AI and Actinomycosis has never been reported before. Failure to detect superinfections of AI lesions with slow-growing pathogens like Actinomyces spp. might contribute to high recurrence rates after immunosuppressive therapy of AI. The present case underlines the potentially multifactorial pathogenesis of the disease and the importance of considering and treating potential infections before initiating immunosuppressive regimens for AI patients.