Hidradenitis suppurativa: Current and emerging treatments

The Efficacy and Safety of Biosimilars in Hidradenitis Suppurativa: A Comprehensive Review

Hidradenitis Suppurativa (HS), also known as Acne Inversa, is a chronic, recurrent inflammatory skin condition primarily affecting apocrine gland-bearing areas, such as the axilla and groin. Characterized by painful nodules, abscesses, and scarring, and has a profound psychological impact on patients. Current treatments aim to manage symptoms and prevent new lesions with a combination of non-pharmacological and pharmacological approaches. Emerging biosimilars, which replicate the efficacy and safety profiles of known biologics at a lower cost, offer new options for treating this debilitating cutaneous disorder. The review summarizes recent studies to explain the role of biosimilars in HS, emphasizing their potential to expand effective treatment options.

Ustekinumab in Hidradenitis Suppurativa: A Systematic Review and Meta-analysis

INTRODUCTION

Hidradenitis suppurativa (HS) is a frequently debilitating, inflammatory skin condition. Patients may have a limited response to adalimumab, currently the only Food and Drug Administration (FDA)-approved biologic treatment for HS. Ustekinumab is an interleukin-12/23 inhibitor that has been utilized in HS, but there is a lack of an updated systematic review on its efficacy and safety. The aim of this study is to perform a systematic review and meta-analysis of the literature on the efficacy and safety of ustekinumab for HS.

METHODS

In October 2022, MEDLINE and Embase databases were searched for articles on ustekinumab in HS. Data extraction was performed on relevant articles by two reviewers. The primary study outcome was the pooled response rate of HS to ustekinumab. A fixed-effects meta-analysis was performed, and Cochran's Q statistic and I squared index were used to assess heterogeneity. Statistical significance was determined at p < 0.05. This article is based on previously conducted studies and does not contain any new studies with human participants or animals performed by any of the authors.

RESULTS

From 2012 to 2022, ten articles (nine case series and one prospective trial) with 88 patients met the inclusion criteria. Patients with reported disease severity had Hurley stage II (17.6%, 12/68) or III (82.4%, 56/68) disease. The majority (80.7%, 71/88) had previously failed at least one biologic treatment. A meta-analysis of all ten studies showed a pooled response rate of 67% (95% CI 0.57-0.76). Study limitations include a small number of patients and randomized controlled trials (RCTs).

CONCLUSIONS

Ustekinumab may be a helpful treatment option to consider for HS that is recalcitrant to first-line biologic therapies, but RCTs are needed to determine optimal dosing regimens and the specific patient populations that would benefit the most from this agent.

Inflammatory loop involving Staphylococcus aureus, IL-36γ, and cathepsin S drives immunity disorders in familial acne inversa keratinocytes

Acne inversa (AI) is an inflammatory skin disease associated with nicastrin (NCSTN) mutations. Despite the dysregulated bacterial-host immune interactions being an essential event in AI, the interaction between bacteria and keratinocytes in AI pathophysiology remains unclear. In this study, the NCSTN gene was suppressed using short hairpin RNA in HaCaT cells. Using RNA sequencing, real-time polymerase chain reaction, and western blotting, the expression of IL-36 cytokines was analyzed. The impact of Staphylococcus aureus on AI keratinocyte inflammation and underlying regulatory molecules was investigated by exposing the HaCaT cells to S. aureus. By stimulating NCSTN knockdown HaCaT cells with IFN-γ, the expression and regulatory mechanism of Cathepsin S (Cat S), an IL-36γ cleavage and activating protease, were investigated. After NCSTN knockdown, the IL-36α expression increased, and the IL-36Ra expression was downregulated. NCSTN/MEK/ERK impairment-induced Krüppel-like factor 4 (KLF4) up-regulation in concert with S. aureus-induced nuclear factor kappa B elevation acts synergistically to promote IL-36γ production with the subsequent IL-8 activation in HaCaT cells. NCSTN/MEK/ERK impairment was also observed in familial AI lesions. IFN-γ-induced Cat S in keratinocytes was enhanced after NCSTN knockdown. The expression of IFN-II pathway molecules was significantly upregulated in both NCSTN knockdown HaCaT cells and familial AI lesions. The Cat S expression was significantly elevated in the patient's AI lesions. Our findings suggested a synergistic relationship between S. aureus and NCSTN/MAPK/KLF4 axis in IL-36γ-induced familial AI keratinocytes.

[Hidradenitis suppurativa]

Hidradenitis suppurativa (HS) is a chronic inflammatory skin and systemic disease that is associated with considerable discomfort and a significant reduction in the quality of life. Despite a significantly increased understanding of the disease, the diagnosis is still delayed for many years. Delayed patient access to suitable treatment often leads to disease progression with increased surgical interventions and the occurrence of possible comorbidities. In recent years, there has been an improved understanding of the pathophysiology and, as a result the authorization of modern therapeutic agents for HS. The treatment of HS is based on three treatment pillars: surgery, antibiotics and biologics. Additionally, risk factors, such as smoking and obesity should be positively influenced. Knowledge of comorbidities and their interdisciplinary treatment is important for the individualized care of patients.

Golimumab and certolizumab pegol for the treatment of hidradenitis suppurativa: a literature review and future perspective

Hidradenitis suppurativa (HS) is an inflammatory skin condition with an underlying inflammatory process. Due to the limited efficacy of available treatments, HS remains a therapeutic challenge. The safety and efficacy of tumor necrosis factor-α (TNF-α) inhibitors, adalimumab, infliximab, and etanercept, are well studied in this patient population, and in some cases, HS was unresponsive to them. In recent years, evidence has been growing regarding the application of other anti-TNFs, including certolizumab pegol (CPZ) and golimumab. We sought to evaluate the overall safety and efficacy of golimumab and CPZ in the management of HS. A comprehensive search was performed on the PubMed, Scopus, Web of Science, and Ovid Embase databases, as well as the Google Scholar search engine from initiation to 31 August 2023. A total of nine and four studies used CPZ and golimumab to treat HS, respectively. Individuals with concomitant inflammatory immune-mediated diseases, pregnant females, and patients who were refractory to previous treatments achieved a Hidradenitis Suppurativa Clinical Response following CPZ administration. Also, golimumab showed promise in treating recalcitrant HS after the failure of other treatments, such as adalimumab and anti-interleukin-1. CPZ and golimumab can be efficacious treatment options for moderate-to-severe HS, especially in patients who are unresponsive to other TNF inhibitors, such as adalimumab.

A review of surgical and reconstructive techniques for hidradenitis suppurativa

Hidradenitis suppurativa (HS) is an inflammatory follicular dermatological condition that typically affects the intertriginous and anogenital regions of the apocrine gland-bearing skin. The management of this chronic and recurring disease necessitates a combination of lifestyle changes, medication, and surgical approaches to achieve the best possible outcomes. While medical treatments are recommended for this multimodal disease, surgical therapy, which is the gold standard of treatment for HS, has proven to be the most effective treatment because it provides long-lasting local disease control, reduces the recurrence of lesions, and ensures complete healing of lesions. In the last decade, there has been exponential growth in research into various surgical techniques and reconstructive care, enabling patients to have more surgical options. There is a wide range of surgical management procedures available, such as incision and drainage, deroofing, excisional surgery, carbon dioxide laser therapy, and skin tissue-sparing excision with electrosurgical peeling. Among these surgical procedures, wide surgical excision is the best option since it can eradicate all the affected lesions. Meanwhile, the preferred approach to reconstruction at various anatomical locations remains debatable. Here, we review a variety of surgical treatments and reconstructive techniques for HS, particularly various flap techniques for the axillary, gluteal, and inframammary regions.

Topical and Systemic Retinoids in the Management of Hidradenitis Suppurativa: A Comprehensive Literature Review

Hidradenitis suppurativa (HS) is a debilitating chronic skin disorder characterized by painful inflammatory nodules, abscesses and sinus tracts involving intertriginous areas and has an adverse impact on patient quality of life. Over the past decade, the therapeutic options of HS have increased significantly to comprise multiple modalities, including topical medication, systemic therapies (mainly antibiotics, retinoids, and biologics), surgical approaches, and lifestyle modifications. Biologics alone or in combination with surgery remain the treatment of choice for moderate to severe disease. However, non-biologic therapies (including retinoids) may be used as monotherapy for mild disease and in combination with biologics and surgical treatment in moderate to severe disease. Retinoids, specifically isotretinoin, acitretin, and alitretinoin, are historically used in the management of HS, supported by anecdotal evidence and with variable treatment response. Although the current American and European guidelines offer different recommendations on the use of retinoids in HS, retinoids remain a valuable ally in HS management. This review provides a comprehensive analysis of the current scientific literature on retinoid therapy (topical and systemic) in HS, highlighting disparities in mechanisms of action, efficacy, and safety to clarify their role in HS treatment.

Rethinking Hidradenitis Suppurativa Management: Insights into Bacterial Interactions and Treatment Evolution

Hidradenitis suppurativa (HS), or acne inversa, is a chronic inflammatory dermatological condition characterized by painful and recurrent nodules and purulent abscesses. HS can have a devastating impact on the quality of life of patients. This condition is commonly localized to the axilla, groin, perineal, and inframammary regions, and can develop fistulas and sinus tracts over time. Its pathogenesis remains elusive and is best characterized at the moment as multi-factorial. Additionally, questions remain about the role of cutaneous dysbiosis as a primary HS trigger or as a secondary perturbation due to HS inflammation. This article features works in relation to HS and its interplay with bacterial microflora. We address current treatment approaches and their impact on HS-related bacteria, as well as areas of therapeutic innovation. In the future, disease-modifying or remittive therapy will likely combine an advanced/targeted anti-inflammatory approach with one that effectively modulates cutaneous and deep tissue dysbiosis.

Cross-Comparison of Inflammatory Skin Disease Transcriptomics Identifies PTEN as a Pathogenic Disease Classifier in Cutaneous Lupus Erythematosus

Tissue transcriptomics is used to uncover molecular dysregulations underlying diseases. However, the majority of transcriptomics studies focus on single diseases with limited relevance for understanding the molecular relationship between diseases or for identifying disease-specific markers. In this study, we used a normalization approach to compare gene expression across nine inflammatory skin diseases. The normalized datasets were found to retain differential expression signals that allowed unsupervised disease clustering and identification of disease-specific gene signatures. Using the NS-Forest algorithm, we identified a minimal set of biomarkers and validated their use as diagnostic disease classifier. Among them, PTEN was identified as being a specific marker for cutaneous lupus erythematosus and found to be strongly expressed by lesional keratinocytes in association with pathogenic type I IFNs. In fact, PTEN facilitated the expression of IFN-β and IFN-κ in keratinocytes by promoting activation and nuclear translocation of IRF3. Thus, cross-comparison of tissue transcriptomics is a valid strategy to establish a molecular disease classification and to identify pathogenic disease biomarkers.

The management of pediatric hidradenitis suppurativa differs between dermatologic and non-dermatologic providers: A retrospective review

BACKGROUND/OBJECTIVES

There is a paucity of pediatric hidradenitis suppurativa (HS) literature. The objective of this study was to characterize differences in management of pediatric HS patients by dermatology versus non-dermatology clinicians.

METHODS

We examined a retrospective cohort of 195 pediatric patients with HS seen at our institution (3/1/19-3/1/20). Two-sample t-tests and two-proportion z-tests were performed.

RESULTS

A total of 76.1% of subjects were seen by dermatology at least once, and of these, 79.1% were referred. HS diagnosis was most often made by dermatology (36.6%), followed by pediatrics (21.6%). Patients managed by dermatology were significantly more likely to have used standard of care therapies (p < .001). Of dermatology-managed patients, 19.7% were currently prescribed a biologic, as compared with zero patients not managed by dermatology. Those managed by dermatology were less likely to undergo surgical excision (13.3% vs. 25.5%, p = .04).

CONCLUSIONS

Our results support increased likelihood of treatment escalation with medical management by dermatologists. Relatively high utilization of referral to dermatology exists, but with only moderate patient adherence. There is a need for improved access to dermatologic care and prospective studies to determine whether differences in specialty management translate to improved patient outcomes.

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.

A Retrospective Review of Laser Therapy for Treatment of Hidradenitis Suppurativa

PURPOSE

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by painful and foul-smelling cystic nodules and sinus tracts in the apocrine gland-bearing regions. The treatment options include topical, intralesional, systemic, and surgical modalities. Currently, the most novel therapy is laser therapy to provide localized treatment without systemic adverse effects. However, data regarding patient outcomes after laser treatment are limited because of the low prevalence of this disease. This study aimed to evaluate the efficacy of laser therapy as a treatment modality for patients with HS.

METHODS

A retrospective review cohort analysis of patients with HS undergoing laser treatment between 2016 and 2021 was conducted. Patient demographics, lesion location(s), Hurley stage, age of onset and diagnosis, treatment length, type, outcomes, and complications were analyzed.

RESULTS

Ninety-four patients met the inclusion criteria; on average, patients were treated with 5.8 laser sessions for 14.8 months with no complications and minor blood loss. Hidradenitis suppurativa progression commonly starts during puberty, with a median onset of 13.8 years and diagnosis of HS at 16.2 years. All patients (n = 94) showed an improvement in HS disease severity: 59.6% completed treatment, 12.0% are currently undergoing treatment, and 26.0% were lost to follow-up.

CONCLUSIONS

Laser therapy is an effective and safe therapy for HS leading to improved quality of life and should be considered in the treatment and management of HS.

Integrative systems biology framework discovers common gene regulatory signatures in multiple mechanistically distinct inflammatory skin diseases

More than 20% of the population across the world is affected by non-communicable inflammatory skin diseases including psoriasis, atopic dermatitis, hidradenitis suppurativa, rosacea, etc. Many of these chronic diseases are painful and debilitating with limited effective therapeutic interventions. However, recent advances in psoriasis treatment have improved the effectiveness and provide better management of the disease. This study aims to identify common regulatory pathways and master regulators that regulate molecular pathogenesis. We designed an integrative systems biology framework to identify the significant regulators across several inflammatory skin diseases. With conventional transcriptome analysis, we identified 55 shared genes, which are enriched in several immune-associated pathways in eight inflammatory skin diseases. Next, we exploited the gene co-expression-, and protein-protein interaction-based networks to identify shared genes and protein components in different diseases with relevant functional implications. Additionally, the network analytics unravels 55 high-value proteins as significant regulators in molecular pathogenesis. We believe that these significant regulators should be explored with critical experimental approaches to identify the putative drug targets for more effective treatments. As an example, we identified IKZF1 as a shared significant master regulator in three inflammatory skin diseases, which can serve as a putative drug target with known disease-derived molecules for developing efficacious combinatorial treatments for hidradenitis suppurativa, atopic dermatitis, and rosacea. The proposed framework is very modular, which can indicate a significant path of molecular mechanism-based drug development from complex transcriptomics data and other multi-omics data.

Metformin has anti-inflammatory effects and induces immunometabolic reprogramming via multiple mechanisms in hidradenitis suppurativa

BACKGROUND

Targeting immunometabolism has shown promise in treating autoimmune and inflammatory conditions. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease involving painful lesions in apocrine gland-bearing skin. Therapeutic options for HS are limited and often ineffective; thus, there is a pressing need for improved treatments. To date, metabolic dysregulation has not been investigated in HS. As HS is highly inflammatory, we hypothesized that energy metabolism is dysregulated in these patients. Metformin, an antidiabetic drug, which is known to impact on cellular metabolic and signalling pathways, has been shown to have anti-inflammatory effects in cancer and arthritis. While metformin is not licensed for use in HS, patients with HS taking metformin show improved clinical symptoms.

OBJECTIVE

To assess the effect and mechanism of action of metformin in HS.

METHODS

To assess the effect of metformin in vivo, we compared the immune and metabolic profiles of peripheral blood mononuclear cells (PBMCs) of patients with HS taking metformin vs. those not taking metformin. To examine the effect of metformin treatment ex vivo, we employed a skin explant model on skin biopsies from patients with HS not taking metformin, which we cultured with metformin overnight. We used enzyme-linked immunosorbent assays, multiplex cytokine assays and quantitative real-time polymerase chain reaction (RT-PCR) to measure inflammatory markers, and Seahorse flux technology and quantitative RT-PCR to assess glucose metabolism.

RESULTS

We showed that metabolic pathways are dysregulated in the PBMCs of patients with HS vs. healthy individuals. In metformin-treated patients, these metabolic pathways were restored and their PBMCs had reduced inflammatory markers following long-term metformin treatment. In the skin explant model, we found that overnight culture with metformin reduced inflammatory cytokines and chemokines and glycolytic genes in lesions and tracts of patients with HS. Using in vitro assays, we found that metformin may induce these changes via the NLR family pyrin domain containing 3 (NLRP3) inflammasome and the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) pathway, which is linked to glycolysis and protein synthesis.

CONCLUSIONS

Our study provides insight into the mechanisms of action of metformin in HS. The anti-inflammatory effects of metformin support its use as a therapeutic agent in HS, while its effects on immunometabolism suggest that targeting metabolism is a promising therapeutic option in inflammatory diseases, including HS.

Advances in surgical treatment of hidradenitis suppurative

Hidradenitis suppurative is a chronic, refractory and recurrent dermatological disease. The disease should be managed by targeted surgical intervention on the basis of medical treatment. Currently, the surgical treatment methods include local treatments like incision and drainage, unroofing, laser therapy, intense pulsed light therapy, photodynamic therapy, as well as complete lesion resection such as skin-tissue saving excision with electrosurgical peeling and extended excision. The clearance range, therapeutic effect, postoperative complications, and recurrence risk vary among the different treatment methods. Local treatments cause less damage, but have high recurrence rates, and are mainly for mild to moderate hidradenitis suppurative patients. Complete lesion resections have relatively low recurrence rates, but may bring more surgical injuries, and postoperative reconstructions are needed, which are mainly for moderate to severe hidradenitis suppurative patients. In this article, the surgical treatment principles and various surgical treatment methods of hidradenitis suppurative are reviewed, to provide a reference for the diagnosis and treatment of this disease in clinical practice.

Assessing unmet needs in patients with hidradenitis suppurativa

The diagnosis and management of hidradenitis suppurativa (HS) varies greatly between providers, often resulting in gaps in care including diagnostic delays and poor outcomes. As dermatologists strive to improve HS management, understanding patient perspectives is key. This study aims to characterize existing gaps in HS care as understood through patients' experiences. This study recruited adult patients with a diagnosis of HS seen at dermatology practices affiliated with Northwestern University. Data were collected through participant surveys and three semi-structured focus groups. Focus group meetings were transcribed verbatim and data were abstracted into themes using conventional content analysis. Six final themes were abstracted after review of 20 pages of transcribed conversation. Four themes centered on improved medical management of HS (access to care, disease-modifying therapies, symptom treatment, prevention of treatment-related adverse events). Two themes centered on supportive care (mental health support, specialized daily wear products). Limitations of this study include single-center recruitment and recall bias introduced by the focus group format. This study identifies six unmet needs for patients with HS and highlights the efficacy of a virtual format for research, conversation, and possibly clinical engagement. Moreover, multiple themes underscore the need for further collaboration across specialties in managing HS.

Treatment Patterns and Healthcare Resource Utilization Among Newly Diagnosed Psoriasis, Psoriatic Arthritis, Axial Spondyloarthritis, and Hidradenitis Suppurativa Patients with Past Diagnosis of an Inflammatory Condition: A Retrospective Cohort Analysis of Claims Data in the United States

INTRODUCTION

Psoriasis (PSO), psoriatic arthritis (PsA), axial spondyloarthritis (axSpA), and hidradenitis suppurativa (HS) are chronic inflammatory diseases (CIDs) often diagnosed and treated individually. However, genetic overlaps exist among CIDs, and patients with one are at risk of developing others within the same spectrum. This analysis characterized treatment patterns along with clinical and economic burdens of newly diagnosed CIDs among patients with an additional past diagnosis of PSO, PsA, axSpA, or HS.

METHODS

This study used MarketScan® databases to examine demographics, treatment patterns, and healthcare resource utilization for patients with ≥ 1 claim for PSO or HS or ≥ 2 claims for PsA or axSpA, and continuous enrollment in the year before (baseline period) and following (follow-up period) the date of first diagnosis (incident diagnosis). Comorbidities and new CID diagnoses with a past diagnosis of PSO, PsA, axSpA, or HS, were examined.

RESULTS

The analysis included 298,794 patients (maximum of 1202 patients with ≥ 1 incident diagnoses): 134,233 had incident PSO; 9914 had incident PsA; 115,194 had incident axSpA; and 40,655 had incident HS. Prevalence of ≥ 1 CID diagnosis among patients with past diagnosis of PSO, PsA, axSpA, or HS was 4959/134,233 (3.7%), 5256/9914 (53.0%), 3205/115,194 (2.8%), and 1180/40,655 (2.9%), respectively. In patients with incident axSpA and past PsA diagnosis, incident axSpA and past HS diagnosis, and incident HS and past PSO diagnosis, steroid and opioid use were high across baseline and follow-up periods and use of biologic disease-modifying antirheumatic drugs increased from baseline to follow-up. Disease-related costs increased absolutely and increased or remained high as a proportion of all-cause costs.

CONCLUSION

Patients with newly diagnosed CIDs and additional past diagnosis of PSO, PsA, axSpA, or HS experienced high treatment utilization and healthcare costs. These findings highlight the need for payers, health technology assessment agencies, clinicians, and other stakeholders to explore the co-management of CIDs, rather than treating them separately.

Differential diagnosis of stage 2, 3 and 4 pressure injuries of the pelvis and lower extremity: a case series

Constant, unrelieved pressure of local tissue, particularly over bony prominences, may provoke damage that progresses to necrosis and pressure injury (PI). Differentiating PIs from conditions of similar appearance is imperative to minimising complications and implementing prompt treatment. This case series describes several conditions that may be mistaken for a PI. Outlined are the key differences in patient history, presentation and clinical cues that assist in correctly identifying the true pathology behind these conditions. Conditions reviewed included: pyoderma gangrenosum; necrotising fasciitis; genital herpes; Marjolin ulcer, Rosai-Dorfman disease; vascular disease; coagulopathies; calciphylaxis; trauma and surgical wounds; pilonidal cysts; graft-versus-host disease; hidradenitis suppurativa; Stevens-Johnson syndrome; epidermolysis bullosa; radiation wounds; spider bites; and end-of-life skin failure pressure ulcers (also known as Kennedy ulcers). Although commonly recognised and diagnosed, stage 2, 3 and 4 PIs occasionally prove to be difficult to pinpoint, with undefined characteristics and similarities in presentation to several other conditions. Therefore, it is clinically vital to be aware of their appearance, risk factors and aetiology in order to make an appropriate patient assessment and avoid misdiagnosis.

Hidradenitis suppurativa and follicular occlusion syndrome: Where is the pathogenetic link?

The follicular occlusion tetrad complex encompasses several entities (hidradenitis suppurativa, acne conglobata, dissecting cellulitis of the scalp, and pilonidal cyst) that share common clinical features, risk factors, and pathophysiology. Follicular occlusion is a crucial triggering mechanism in the etiology in each of these disorders, leading to development of distinctive skin lesions such as deep-seated nodules, abscesses, comedones, and draining sinuses, often with accompanying scarring. Despite the fact that the follicular occlusion tetrad components manifest multiple similarities, they also exhibit many differences among themselves and require individual approaches and treatment.

A bibliometric analysis of hidradenitis suppurativa literature over the past 50 years

BACKGROUND

We aimed to describe the existing literature on hidradenitis suppurative (HS) in the last 50 years and the key processes made over time.

METHODS

On July 27, 2022, we searched for HS studies published in the last 50 years (from 1972 to 2022) using Web of Science. The search was made using the keywords "Hidradenitis Suppurativa" and "Acne Inversa." The data are subdivided according to publications and citations rate, country, publication year, journal and impact factor, keywords analysis of top 100 cited papers study design, and pediatric versus adults.

RESULTS

In total, 5072 documents were retrieved. The annual number of HS publications has increased over the years. The manuscript with the highest citation number was by Zouboulis et al., a total of 552 citations from 2015. The manuscript with the highest citation rate per year was by Mantovani et al., with a citation rate of 70.7/year. According to keywords analysis among the top 100 cited papers, most of the articles focused on management, followed by the pathogenesis of HS. Only 805 out of 5072 (15.8%) HS articles described the disease among children.

CONCLUSIONS

In the current analysis, we shed light on HS's transformations over the last 50 years. In addition, we described the 100 top cited papers and other essential characteristics not examined before, such as HS research in children, gender bias research, specific pharmacological therapy with keyword analysis, comorbidities, preventative care, and publications per country after controlling for population.

[Guidelines for the Management of Patients with Hidradenitis Suppurativa]

Hidradenitis suppurativa is a chronic and recurrent inflammatory dermatosis characterized by the presence of inflammatory nodules and abscesses in the apocrine gland-rich areas that may progress to suppurative fistulas and scars. Despite being considered one of the dermatological conditions with the greatest impact on patient quality of life, it is often underdiagnosed. Hidradenitis suppurativa, especially in its severe forms, is associated with numerous comorbidities, so a holistic and multidisciplinary perspective is crucial for the management of these patients. The therapeutic approach is complex and challenging. The medical treatment options are diverse and must be adapted to clinical presentation and disease severity. Surgical therapy should be considered as an adjuvant to medical treatment, particularly in refractory cases and in the presence of scars or anatomical and/or functional mutilation. These recommendations reflect the main aspects of the management of the patient with hidradenitis suppurativa and are addressed to all healthcare professionals who take part in their follow-up.

Real-World Findings on the Characteristics and Treatment Exposures of Patients with Hidradenitis Suppurativa from US Claims Data

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, debilitating, and painful inflammatory skin disease that significantly and negatively impacts patients' quality of life. The prevalence of HS in the USA is estimated to be 0.10%, with worldwide reports suggesting a prevalence closer to 1%. There is limited real-world evidence available on the care of patients with HS. We aimed to evaluate the trends in clinical care and treatment in the patient population with HS in the USA in a real-world setting.

METHODS

A cohort study was conducted using claims data from IBM MarketScan Databases, including the US Commercial Claims and Encounters with Medicare Supplemental and Coordination of Benefits (CCAE+MDCR) database and IBM US Medicaid database.

RESULTS

The annual prevalence of HS increased from 0.06% (2008) to 0.14% (2017), and from 0.17% (2008) to 0.31% (2017) among CCAE+MDCR and Medicaid patients, respectively. Dermatologist visits increased from 31.9% (2008) to 47.8% (2019) in CCAE+MDCR patients, and decreased from 10.9% (2008) to 8.5% (2018) in Medicaid patients. Opioid use decreased from 45.4% (2008) to 25.5% (2019) among CCAE+MDCR patients, and from 71.3% (2008) to 48.1% (2018) among Medicaid patients. Only 8.4% of CCAE+MDCR patients and 5.8% of Medicaid patients were exposed to any biologic in 2018.

CONCLUSIONS

Improved care and treatment of HS over the last decade, including the emergence of new treatments, have been accompanied by an increase in awareness and reported prevalence of the disease. However, there are still gaps in access to dermatologic care and low utilization of biologic therapies among patients with HS. INFOGRAPHIC.

Adalimumab, Ustekinumab, and Secukinumab in the Management of Hidradenitis Suppurativa: A Review of the Real-Life Experience

To date, adalimumab (ADA) is the only biotechnology drug approved for the management of hidradenitis suppurativa (HS), an inflammatory skin condition. However, it quickly became apparent that the efficacy of adalimumab in daily practice was highly variable. In our review, we highlighted the current evidence from literature on the use of biologics in HS in a real-life setting, particularly adalimumab, secukinumab and ustekinumab. Data on the effectiveness and safety of biologic drugs in HS management have been analyzed. Even if the results are promising, more studies are needed. In our opinion, the armamentarium of drugs for HS management is increasing, and treatment will be based on a tailored-tail approach, minimizing the risk of adverse events. In this context, we want to point out the reported effectiveness and safety data concerning adalimumab, ustekinumab and secukinumab as well as ixekizumab.

Surgical Management of Hidradenitis Suppurativa: Factors Associated with Postoperative Complications and Disease Recurrence

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder. Treatment of HS remains challenging, and surgical procedures commonly follow attempts of conservative therapy. To date, a consensus regarding the optimal surgical technique has not been reached, and the implications of conservative therapy on future surgical outcomes have yet to be studied.

METHODS

A retrospective cohort study of 65 patients surgically treated for HS at a tertiary care center was conducted. Patients' medical records were screened for demographical, clinical, and surgical characteristics. Statistical analysis was conducted to determine associations with postoperative complications and disease recurrence.

RESULTS

Fifty patients (75.8%) were treated with systemic antibiotics before opting for surgical resection. Previous treatment with systemic rifampicin was associated with higher rates of postoperative complications (P = 0.029); however, systemic cephalexin and topical clindamycin were associated with a lower rate of complications (P = 0.007 and 0.040, accordingly). Medical history of smoking and surgical management with split-thickness skin grafts were associated with higher rates of postoperative complications (P = 0.012 and 0.014, accordingly). Patients with a greater number of lesions, and those treated with split-thickness skin graft, had higher rates of disease recurrence (P = 0.0018 and 0.003, accordingly).In a multivariate analysis a greater number of lesions (P = 0.0498) and the use of autologous split-thickness skin graft (P = 0.022) were independently associated with higher rates of disease recurrence.

CONCLUSIONS

Previous conservative medical therapy bears the potential to modulate postoperative outcomes in HS patients, and should be taken into consideration. Despite reports of reliable results with split-thickness skin grafts, we found them to be associated with increased rates of diseases recurrence and postoperative complications.

Non-surgical treatment of hidradenitis suppurativa: the role of cryotherapy

Background

Hidradenitis suppurativa is a chronic and recurrent inflammatory disease with a great impact on a patient's quality of life, due to the painful involvement of very sensitive areas, such as the groin, mammary area, and genitals, with malodourous discharge. Multiple treatment options are available; however, no single treatment is effective for all patients, and usually, a combination of medical therapy with various surgical and physical procedures is provided. Cryotherapy is not a routine technique to treat HS, although usually available in the majority of medical clinics, and is cheaper than laser and surgical treatments. The aim of this study was to evaluate the effectiveness of cryotherapy on persistent HS nodules, to reduce the burden of local disease.

Materials and methods

Retrospective observational study in all patients treated with liquid nitrogen cryotherapy for persistent nodules of hidradenitis suppurativa in the last 2 years, with at least 6 months of follow-up after the procedure. Disease severity was assessed with Hurley staging and sonographic staging according to SOS-HS (18 MHz probe, Esaote-MyLab™). The results were scored with a 0-3 points scale, as complete remission (3), partial response (2 to 1), or no response (0), after one session of treatment. Local cleansing and antiseptic treatment after the procedure was the same as previously performed in each patient, not to influence recovery.

Results

In total, 23 patients were included, with a total of 71 persistent nodules treated with a single cryotherapy session. The treatment has been effective in 63 out of 71 nodules treated (88.7%), and the patients attested that they recommend the treatment, the discomfort during recovery was minimal, and the management was not different from daily routine. Persistence was considered as having a failure rate (11.3% overall) and occurred in 7.5% of the nodules of the axillary region, 18.2% on the groin, and 11.2% for nodules of the gluteal region.

Conclusion

Cryotherapy is a simple and effective procedure for the treatment of persistent nodules of HS not responding to medical therapy, and it is a valid alternative to local surgery or laser ablation.

Hidradenitis suppurativa and inflammatory bowel disease in a nested case-control study

BACKGROUND

Association between Hidradenitis Suppurativa (HS) and Inflammatory Bowel Disease (IBD) has been suggested.

AIMS

To assess characteristics of HS and IBD in patients with or without concomitant IBD.

METHODS

In a prospective, nested case-control study, each IBD patient with concomitant HS (Case) was retrospectively matched with 4 patients with HS and no IBD (Controls) for gender and age (±5 years).HS was classified according to the Hurley score and the International Hidradenitis Suppurativa Severity Score System (IHS4). Data were expressed as mean (Standard Deviation). Statistical analysis included Student-t Test or Mann-Whitney Test, χ2 test, univariate and multivariate logistic regression.

RESULTS

The study population included 125 patients with HS: 25 with IBD, 100 matched Controls with no IBD. IBD group included 19 (76%) Crohn's disease and 6 (24%) Ulcerative Colitis patients. Obesity, familial HS and perianal HS were less frequent in Cases than in Controls (1[4%] vs 25(25%];p = 0.02; 1[4%] vs 21(21%];p = 0.04; 1[4%] vs 31(31%];p = 0.005, respectively).HS was less severe in Cases when assessed by the IHS4 (5.9 ± 4 vs 9 ± 6.7;p = 0.04).Complete drug-induced response for HS was more frequent in IBD (13[53%] vs28 (28%]; p = 0.04).

CONCLUSION

Clinical characteristics of HS and of patients differed between Cases and Controls. Present findings suggest the need to appropriately search and assess skin lesions compatible with HS in IBD.

Outcomes and Reliability of Perforator Flaps in the Reconstruction of Hidradenitis Suppurativa Defects: A Systemic Review and Meta-Analysis

INTRODUCTION

Hidradenitis suppurativa (HS) is a common and debilitating disease, in which the only effective treatment involves a wide excision of the affected skin. Secondary wound healing and skin grafting are two well-known options for managing these defects, but perforator flaps provide a new therapeutic alternative by ensuring reconstructions of large defects, reducing donor site morbidity, and enhancing functional recovery. The aim of this study was to achieve a systematic review of perforator flaps use in HS.

PATIENTS AND METHODS

PubMed and Cochrane databases were searched from 1989 to 2021. The PRISMA statement was used in the study selection process and the review was registered on PROSPERO. Furthermore, patient characteristics, operative technique, complications, and recurrences were searched.

RESULTS

Thirty-six articles were selected including 286 patients and 387 flaps. Axillary localization was mostly represented (83.2%). Direct donor site closure was achieved in 99.1% of cases. In total, 15.1% of the flaps presented at least one of the following complications: wound dehiscence (5.5%), partial necrosis (2.9%), hematoma or seroma (2.1%), infection (2.1%), venous congestion (1.8%), and nerve injury (0.3%). Two cases of total necrosis were recorded. Recurrence of the disease was observed in 2.7% of the defects.

CONCLUSIONS

Pedicled perforator flaps are a reliable and reproducible technique in the reconstruction of HS defects. They are associated with a low recurrence rate while ensuring an effective reconstruction with reduced morbidity and faster recovery compared to the techniques classically used in this indication.

The identification of polyvalent protective immunogens and immune abilities from the outer membrane proteins of Aeromonas hydrophila in fish

Among aquaculture vaccines, polyvalent vaccines (for immunoprotection against multiple bacterial species) are more efficient and can better avoid bacterial resistance and antibiotic residues in fish. Here, 15 outer membrane proteins (OMPs) of Aeromonas hydrophila were cloned and purified, and mouse antisera were prepared. Passive immunization to Carassius auratus showed that four OMPs sera (OmpW, OmpAII, P5, and AHA2685) and the entire OMPs serum held effective immunoprotection against A. hydrophila infection. Furthermore, the active immunization of four OMPs to C. auratus showed that OmpW, OmpAII, P5, and AHA2685 held effective immunoprotection against A. hydrophila, and OmpW held active cross-protection against Vibrio alginolyticus. The mechanisms of these four candidate vaccines in triggering immune responses were subsequently explored. They all could activate innate immune responses in active immunization, down-regulate (p < 0.05) the inflammation-related genes expression to reduce the inflammatory reaction induced by A. hydrophila, and down-regulate (p < 0.05) antioxidant-related factors to reduce the antioxidant reaction for bacterial infection. Noteablely, the four OMPs had protective abilities on kidney and spleen tissues of C. auratus after challenged with A. hydrophila and V. alginolyticus by histopathological observation. Collectively, our results identify OmpW as a polyvalent vaccine candidate, and OmpAII, P5, and AHA2685 as vaccine candidates against A. hydrophila infection in fish.

Practical Guidelines for Managing Patients With Hidradenitis Suppurativa: An Update

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease that is characterized by the formation of comedones, papules, nodules, abscesses and sinus tracts in the axillary, inframammary, groin, and gluteal areas. Up to 3.8% of the Canadian population has HS, though due to a lack of awareness of HS, many patients are initially misdiagnosed and do not receive adequate treatment early on in the disease course. Once a diagnosis of HS is made, developing an effective management plan can be a dilemma for many providers. There is significant variability in response to any given therapy within the HS patient population and many HS patients have other medical comorbidities which must be taken into consideration. The aim of this review is to provide a practical approach for all healthcare providers to diagnose and manage HS and its associated comorbidities. A sample electronic medical record template for HS management was developed by the Canadian Hidradenitis Suppurativa Foundation Executive Board and is intended for use in clinical settings. This will help to increase collaboration between primary healthcare providers, dermatologists, and other medical specialists and ultimately improve the quality of care that HS patients receive.

Antibiotic resistance in dermatology: The scope of the problem and strategies to address it

Antibiotic resistance is a growing health concern that has attracted increasing attention from clinicians and scientists in recent years. Although resistance is an inevitable consequence of bacterial evolution and natural selection, misuse and overuse of antibiotics play a significant role in its acceleration. Antibiotics are the mainstay of therapy for common dermatoses, including acne and rosacea, as well as for skin and soft tissue infections. Therefore, it is critical for dermatologists and physicians across all disciplines to identify, appropriately manage, and prevent cases of antibiotic resistance. This review explores dermatologic conditions in which the development of antibiotic resistance is a risk and discusses mechanisms underlying the development of resistance. We discuss disease-specific strategies for overcoming resistant strains and improving antimicrobial stewardship along with recent advances in the development of novel approaches to counter antibiotic resistance.

Effects of the modified excision combined with bidirectional photodynamic therapy on refractory hidradenitis suppurativa: a retrospective study

To describe the clinical features of refractory hidradenitis suppurativa (HS) patients (Hurley stageII and stage III) and evaluate the efficacy of combined treatment of the modified excision with bidirectional photodynamic therapy (PDT). A retrospective, multicenter study was conducted in 35 refractory HS patients. They were treated with the modified excision combined with bidirectional PDT. The outcomes, patients' satisfaction, adverse effects, and the Dermatology Life Quality Index (DLQI) were observed. There were more males than females (6:1). The axilla was the most frequently affected region (37.5%). All patients had experienced treatment failures before and had good response to our combined therapy (clearance rate > 75%). The average time required for complete wound healing was 11 days. After 1 year of follow-up, no significant recurrence was observed. The DLQI decreased significantly after the combined treatment. The comprehensive evaluation of scar and the deformation showed good cosmetic results after treatment. Reversible adverse events such as small patchy blackness, necrosis, or ulcer in the tip of the flap occurred in six patients (17.1%). Of the 35 patients, 30 were very satisfied with the treatment. This case series finds that the modified excision combined with bidirectional PDT may hold promise for radical treatment of Hurley stage II and stage III.

New and Emerging Targeted Therapies for Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease deriving from the hair follicles. The formation of inflammatory nodules, abscesses, fistulas, and sinus tracts is characterized by a large inflow of key pro-inflammatory mediators, such as IFN-γ, TNF-α, IL-1, IL-17, and IL-12/23. Adalimumab is currently the only Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved biologic therapy for moderate to severe HS in adults and adolescents. However, the long-term effectiveness of this TNF-α inhibitor in HS patients has shown to be highly variable. This review aims to review the evidence for emerging therapies that target the main pro-inflammatory cytokines in HS pathogenesis. A review of the literature was conducted, using the PubMed and Google Scholar repositories, as well as Clinicaltrials.gov. Presently, the most promising biologics in phase III trials are anti-IL-17 antibodies, secukinumab, and bimekizumab. Furthermore, an anti-IL-1 biologic, bermekimab, is currently in phase II trials, and shows encouraging results. Overall, the clinical efficacies of all new targeted therapies published up to this point are limited. More studies need to be performed to clarify the precise molecular pathology, and assess the efficacy of biological therapies for HS.

Hidradenitis suppurativa: racial and socioeconomic considerations in management

Studies on hidradenitis suppurativa (HS) have found an increased prevalence of HS in skin of color and lower socioeconomic status patients, although the reasons for these differences are unclear. Demographic and therapeutic studies of HS originate primarily from developed Western countries, and data from low- and medium-income countries (LMIC) remain comparatively limited. In this review paper, we discuss differences in clinical presentation and comorbidities between racial and socioeconomic subpopulations and describe the genetic, biomedical, psychosocial, and ecological factors that may explain the associations between HS and skin of color and socioeconomic status. We highlight biomedical treatment considerations for LMIC including cost effective and less complex treatment strategies. We touch on population-based strategies to address the social determinants of health in HS management and discuss additional challenges arising from the COVID-19 pandemic.

Vulvar Neoplasms (Part II)

Vulvar disease is common, and urologists are often the first providers to see patients with a vulvar skin condition. Primary vulvar dermatoses can be localized to the anogenital area or a manifestation of more diffuse cutaneous disease. Additionally, secondary dermatoses can develop from exogenous agents and inflammatory vaginitis. Vulvar conditions are challenging to diagnose due to location and different types of skin and mucosal epithelium involved. Herein, we provide an overview of non-infectious inflammatory vulvar dermatoses (Part I) and benign and malignant vulvar neoplasms (Part II), grouped by morphologic findings. We include diagnostic evaluation, workup, and management of these conditions.

IL-17RA blockade by brodalumab decreases inflammatory pathways in hidradenitis suppurativa skin and serum

BACKGROUND

Hidradenitis suppurativa (HS) is an inflammatory skin disease with dysregulation of the IL-17 axis. Recently we reported clinical benefit of brodalumab, a human anti-IL-17 receptor A (IL-17RA) monoclonal antibody, in moderate-to-severe HS.

OBJECTIVES

To characterize the molecular response to brodalumab in HS skin and serum, and to identify biomarkers of treatment response.

METHODS

Ten participants that received 210 mg/1.5mL brodalumab subcutaneously at week 0, 1, 2, 4 and every 2 weeks after were included in this molecular profiling study (NCT03960268). RNA-sequencing and immunohistochemistry of nonlesional, perilesional and lesional HS skin biopsies, and Olink high throughput proteomics of serum at baseline, week 4 and week 12 were assessed.

RESULTS

At week 12, brodalumab led to a decrease of overall inflammation, and improvement of psoriasis-, keratinocyte- and neutrophil-related pathways. Despite perilesional and lesional skin having no differentially expressed genes at baseline, treatment response was best assessed in perilesional skin. In serum, brodalumab treatment decreased pathways involved in neutrophil inflammation. Patients with higher baseline expression of neutrophil-associated Lipocalin-2 (LCN2) in the skin and IL-17A in the serum demonstrated greater decreases of HS-related inflammatory cytokines as measured in skin biopsies at week 12.

CONCLUSIONS

IL-17RA inhibition by brodalumab impacts several pathogenic inflammatory axes in HS. Perilesional skin provides a valid and robust assessment of treatment response. Expression of LCN2 in skin and IL-17A in serum may be used as biomarkers to stratify patients that may have a superior molecular response to brodalumab =.

Paradoxical Hidradenitis Suppurativa during Biologic Therapy, an Emerging Challenge: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease usually occurring after puberty with painful, deep-seated, inflammatory lesions in the apocrine gland-bearing areas of the body. Although HS pathogenesis is still unproven, recent major research advantages have increased our knowledge of the mechanisms behind HS lesions. Particularly, follicular occlusion followed by follicular rupture has been shown to be crucial to HS development, leading to immune response activation, and resulting in typical clinical HS lesions. Moreover, an increased and imbalanced cytokine production, such as interleukin (IL) 17 and tumor necrosis factor (TNF) α, may play a role in HS. In recent years, paradoxical adverse events have been described during treatment. Since the recent increased use of biologic treatments in HS, an increased number of paradoxical HS occurrences have been reported. In this review, we analyzed all current data on paradoxical HS triggered by biological drugs.

Colchicine in Managing Skin Conditions: A Systematic Review

(1) Background: Colchicine is a natural alkaloid with anti-inflammatory properties used to treat various disorders, including some skin diseases. This paper aims to incorporate all the available studies proposing colchicine as a treatment alternative in the management of cutaneous conditions. (2) Methods: In this systematic review, the available articles present in various databases (PubMed, Scopus-Embase, and Web of Science), proposing colchicine as a treatment for cutaneous pathological conditions, have been selected. Exclusion criteria included a non-English language and non-human studies. (3) Results: Ninety-six studies were included. Most of them were case reports and case series studies describing colchicine as single therapy, or in combination with other drugs. Hidradenitis suppurativa, pyoderma gangrenosum, erythema nodosum, erythema induratum, storage diseases, perforating dermatosis, bullous diseases, psoriasis, vasculitis, acne, urticaria, stomatitis, actinic keratosis, and pustular dermatosis were the main diseases discussed in literature. Although the therapeutic outcomes were variable, most of the studies reported, on average, good clinical results (4) Conclusions: Colchicine could be, as a single therapy or in combination with other drugs, a possible treatment to manage several skin diseases.

Effectiveness and safety of topical 15% resorcinol in the management of mild-to-moderate hidradenitis suppurativa: A cohort study

Antibiotics remain one of the main treatment alternatives in mild-to-moderate hidradenitis suppurativa. The use of topical 15% resorcinol reduces antibiotic pressure and the generation of resistance. However, knowledge on its efficacy and safety is limited. This single-center, prospective, follow-up cohort study evaluated topical 15% resorcinol every 12-h response at 16 weeks. Those individuals with mild-to-moderate hidradenitis suppurativa (Hurley I-II) who started treatment with topical resorcinol monotherapy between April 2019 and May 2020 were eligible for follow-up. The primary endpoint for effectiveness was the proportion of patients who achieved an overall clinical response (complete or partial response) at week 16, evaluated as intention-to-treat. Responses were measured according to the Hidradenitis Suppurativa Clinical Response index. Target lesion size was measured clinically and by ultrasonography. Quality of life was assessed through the Dermatology Life Quality Index (DLQI) questionnaire. Safety was measured by recording the adverse events reported during the follow-up period. A total of 32 patients were enrolled (mean age, 40.1 years [95% confidence interval, 35.7-44.4]; women, 20 [62.5%]; Hurley I, 17 [53.1%]). Under the intention-to-treat analysis, 68.8% (n = 22) of the patients achieved a clinical response. A ≥50% reduction in the size of the main lesion was observed in 56.3% of the patients (n = 18). Some 65.6% (n = 21) of the patients had a ≥50% reduction (improvement) in their baseline DLQI score. Fifty percent of patients who completed the follow-up period experienced adverse events, all of which were local, mild, and transient and did not lead to discontinuation of resorcinol. To conclude, in this cohort study, topical 15% resorcinol was shown to be effective for mild-to-moderate hidradenitis suppurativa and to have a positive impact on quality of life with an acceptable safety profile.