Hidradenitis suppurativa and diabetes mellitus: updated systematic review and adjusted meta-analysis

Medical Nutrition Therapy in Dermatological Diseases: A Joint Consensus Statement of the Italian Association of Dietetics and Clinical Nutrition (ADI), the Italian Society of Dermatology and Sexually Transmitted Diseases (SIDeMaST), the Italian Society of Nutraceuticals (SINut), Club Ketodiets and Nutraceuticals "KetoNut-SINut" and the Italian Society of Endocrinology (SIE), Club Nutrition, Hormones and Metabolism

Dermatological diseases such as acne, hidradenitis suppurativa (HS), and psoriasis are driven by chronic inflammation and oxidative stress. Emerging evidence highlights the role of nutrition in modulating these conditions, particularly through dietary patterns rich in antioxidants, polyphenols, and unsaturated fatty acids. RECENT FINDINGS: The Mediterranean diet (MedDiet) has demonstrated potential benefits due to its anti-inflammatory and immunomodulatory effects, while very low-energy ketogenic therapy (VLEKT) has shown promise in rapidly improving disease severity. Specific nutrients, including omega-3 fatty acids, probiotics, and micronutrients, may further contribute to disease management. However, the current literature is limited by small-scale studies and the lack of standardized dietary guidelines. PURPOSE OF REVIEW: This Consensus Statement, developed collaboratively by the Italian Association of Dietetics and Clinical Nutrition (ADI), the Italian Society of Dermatology and Sexually Transmitted Diseases (SIDeMaST), the Italian Society of Nutraceuticals (SINut), Club Ketodiets and Nutraceuticals "KetoNut-SINut" and the Italian Society of Endocrinology (SIE), Club Nutrition, Hormones and Metabolism, aimed to establish an evidence-based framework for medical nutrition therapy (MNT) of the most common inflammatory skin diseases, including acne, HS and psoriasis.

Endotyping Insulin-Glucose Homeostasis in Hidradenitis Suppurativa: The Impact of Diabetes Mellitus and Inflammation

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease often associated with metabolic disorders such as diabetes mellitus. Recent research suggests a link between systemic inflammation and insulin-glucose dysregulation in HS. This study investigates the relationship between insulin-glucose homeostasis, diabetes mellitus and the haptoglobin concentration in HS patients. Methods: We assessed 95 HS patients and 49 controls using validated fasting-based function tests, including the Structural Parameter Inference Approach (SPINA), Homeostasis Model Assessment (HOMA) and Quantitative Insulin Sensitivity Check Index (QUICKI). Results: The HS patients had a significantly higher fasting insulin concentration (97.2 vs. 69.0 pmol/L, p = 0.035), increased insulin resistance (HOMA-IR: 3.47 vs. 2.57, p = 0.016) and impaired insulin sensitivity (SPINA-GR: 1.34 vs. 1.76 mol/s, p = 0.017). In diabetes, the insulin sensitivity was more strongly reduced (SPINA-GR: 0.61 vs. 1.41 mol/s, p = 0.0057) and the insulin resistance increased (HOMA-IR: 7.3 vs. 3.2, p = 0.017). Higher haptoglobin concentrations were accompanied by worse glycaemic control, demonstrating a significantly elevated fasting glucose (5.77 vs. 5.11 mmol/L, p = 0.043) concentration and HbA1c (5.7% vs. 5.4%, p = 0.0081) fraction. Conclusions: Our findings suggest that chronic inflammation in HS contributes to metabolic dysregulation, worsening insulin resistance and glycaemic control, particularly in those with elevated haptoglobin or diabetes.

A comprehensive systemic review and meta-analysis of the association between lipid profile and hidradenitis suppurativa

BACKGROUND

While several studies have suggested a connection between Metabolic Syndrome (MetS) and Hidradenitis Suppurativa (HS), a definitive analysis confirming the association between lipid abnormalities and HS based on actual lipid values is lacking. Previous research, using odds ratios from ICD codes, indicates links between elevated triglycerides and low high-density lipoprotein levels with HS. However, these findings may not fully represent real-life situations, as no comprehensive analysis using actual lipid measurements has been performed.

OBJECTIVES

To examine the relationship between lipid profile values-total cholesterol, triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL)-and HS.

METHODS

A comprehensive search of PubMed, Cochrane Library, and Embase was conducted to identify studies reporting lipid profiles in HS patients. A meta-analysis using standardized mean differences (SMDs) was performed to assess the association between lipid abnormalities and HS.

RESULTS

The meta-analysis found that HS patients had significantly higher TG levels (SMD = 0.28, 95% CI: 0.09-0.47, P = 0.004) and lower HDL levels (95% CI: -0.53 to -0.16, P < 0.001) compared to healthy controls. No significant differences were observed in total cholesterol (SMD = 0.01, 95% CI: -0.19-0.21, P = 0.93) and LDL levels (SMD = 0.04, 95% CI: -0.10-0.17, P = 0.61). These results corroborate earlier studies linking HS with dyslipidemia, particularly hypertriglyceridemia and hypo-HDL cholesterolemia, with the added strength of using actual lipid values.

CONCLUSIONS

This study confirms the association between hypertriglyceridemia and low HDL cholesterol in HS patients, highlighting the broader systemic association of the condition. Dermatologists should monitor lipid profiles in HS patients to mitigate potential cardiovascular risks through early detection and management.

Management of hidradenitis suppurativa in the inpatient setting: a clinical guide

Hidradenitis suppurativa (HS) is a chronic inflammatory disease that affects the axilla, inframammary folds, buttocks, inner thighs, and anogenital regions. Patients with moderate to severe HS often seek care in the emergency department and may require hospitalization; however, the lack of clear admission criteria and management guidelines presents significant challenges. To address these issues, we conducted a clinical review aimed at hospitalists and consulting dermatologists considering hospital admission for patients experiencing severe HS flares. Admission offers a unique opportunity to optimize care through specialized consultations, pain management, rescue therapy, and surgical planning. Furthermore, multimodal treatments, particularly biologics, are needed to achieve clinical remission in severe disease. Streamlining care during hospitalization for the early initiation of these therapies can significantly improve flare management and overall clinical outcomes for HS patients. This review aims to improve care for HS by providing clear and comprehensive guidance on its management in the inpatient setting.

Genetic Susceptibility to Hidradenitis Suppurativa and Predisposition to Cardiometabolic Disease

Importance

Hidradenitis suppurativa (HS) is associated with an increased prevalence of cardiovascular diseases compared with the general population. Any association between polygenic risk for HS, risk of incident cardiometabolic outcomes, and the plasma proteome is unclear.

Objective

To investigate the genetic correlation between HS and cardiometabolic disease.

Design, Setting, and Participants

This cohort study used a polygenic risk score (PRS) for HS to examine the risks of coronary artery disease (CAD) and diabetes and identify changes in the plasma proteome in individuals of European ancestry from the UK Biobank. Participants were enrolled from January 1, 2006, to December 31, 2010. End of follow-up was January 1, 2023. Correlations were assessed between HS susceptibility and cardiometabolic traits using linkage disequilibrium score regression. Odds ratios were assessed in logistic regressions. The risk of incident CAD and diabetes was estimated in cause-specific survival models designed as time-to-event analyses.

Exposure

The PRS for HS.

Main Outcomes and Measures

Main outcomes were CAD and diabetes diagnosis measured by logistic regressions and incident disease measured by Cox proportional hazards regression models adjusted for sex, age, body mass index, and smoking status.

Results

The study included 391 481 individuals (median [IQR] age, 58 [51-64] years; 209 235 [53%] female). Genetic variants for HS correlated significantly with variants associated with CAD, diabetes, and plasma levels of high-density lipoprotein cholesterol, triglycerides, and C-reactive protein. Compared with the low-risk group, a high PRS for HS (≥75th percentile) conferred odds ratios of 1.09 (95% CI, 1.06-1.12; P < .001) for CAD and 1.13 (95% CI, 1.10-1.17; P < .001) for diabetes. Estimates remained consistent when examining only incident CAD and diabetes. The PRS for HS was significantly associated with altered expression of 58 plasma proteins. Integrating this proteomic profile and the PRS for HS in a machine learning model improved prediction of CAD and diabetes compared with a reference model based on sex, age, and body mass index.

Conclusions and Relevance

These findings suggest that a high genetic risk of HS is associated with increased risk of subsequent CAD and diabetes and altered composition of the plasma proteome. Additional investigation into the identified proteins and their potential roles as drug targets is warranted.

Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by the formation of nodules, abscesses, and fistulae at intertriginous sites. Pain, pruritus, malodor, and suppuration have a significant impact on quality of life for HS patients. Prevalence figures vary greatly in the literature from 0.05% to 4.1%, and HS is more common in females. The current understanding of the etiology and pathogenesis of HS is incomplete; numerous hypotheses concern the interplay of lifestyle factors, skin microbiota, genetics, and a dysregulated immune system. Due to its phenotypic heterogeneity and multifactorial pathogenesis, HS is a complex disease that can prove challenging to manage. Two approved biologic therapies for the management of HS have led to clinical response in approximately 50% of treated patients. New therapies targeting the interleukin (IL)-1, IL-17, IL-36, and Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways are in ongoing clinical trials, and preliminary data offer hope for greater clinical efficacy in HS in the future.

Epidemiology of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent skin disease affecting hair follicles in predominantly intertriginous areas, characterized by deep, painful nodules and abscesses, fistulas, sinus tracts, and scarring. The estimated global prevalence of HS is highly variable, as revealed in a growing body of published literature, and ranges from 0.053% to 4.1%. In North American and European patients, HS is three times more common in women than men, whereas in South Korea and Japan, male predominance is found. The disease most frequently manifests itself between the ages of 18 and 29. Numerous published studies have reported the association between smoking, obesity, and HS, although there are limitations in confirming the causal relationship due to the retrospective design of the available studies. Case-control studies have frequently evaluated the association between HS, metabolic syndrome, and other systemic comorbidities. Due to increased mental health problems, a higher risk of suicide in patients with HS has been reported. We provide up-to-date evidence about the epidemiology, genetic and environmental risk factors, comorbidities, and quality of life of patients with HS. The divergence in HS frequency, possibly due to differences in populations and methodologies, remains to be explained in future worldwide studies.

Obesity and hidradenitis suppurativa: targeting meta-inflammation for therapeutic gain

Hidradenitis suppurativa (HS) is a chronic, inflammatory condition of the pilosebaceous unit. The typical patient with HS is characterized as someone with obesity, who smokes and who has nodules, abscesses and/or draining tunnels predominantly distributed in intertriginous skin. It has been established that lifestyle and genetic factors are the main pathophysiological drivers of HS. In this critical review, we explore the interrelatedness of meta-inflammation, obesity and HS and discuss if and how this relationship may be manipulated for a therapeutic end.

Risk of Chronic Kidney Disease in Hospitalized Patients with Hidradenitis Suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is associated with several comorbidities such as diabetes mellitus and cardiovascular diseases. These comorbidities are also risk factors for chronic kidney disease (CKD), yet little is known about the risk of CKD in HS patients.

OBJECTIVES

The objective was to study the prevalence of CKD in HS patients.

METHODS

Cross-sectional population-based study using the United States National Inpatient Sample database between January 1, 2002 and December 31, 2012 was performed.

RESULTS

We identified 23,767 hospital admissions for HS patients and 95,068 admissions for age- and gender-matched controls. The prevalence of CKD in HS patients was 6.3% (1,497/23,767) compared to non-HS controls which was 4.3% (4,052/95,068). The association of CKD was strongest in HS patients, who were ≥60 years old, 16.9% (475/2,811), male 7.3% (695/9,556), obese 7.8% (407/5,209), diabetic 12.5% (890/7,105), hyperlipidemic 13.3% (416/3,126), and had cardiovascular diseases 12.5% (631/5,045). The crude odds ratio of CKD in HS patients was 1.5 (95% CI: 1.420-1.605) compared to non-HS patients. The association remained significant after adjusting for important covariates with adjusted odds ratio of CKD in HS patients of 1.1 (95% CI: 1.014-1.176) compared to non-HS patients.

CONCLUSIONS

Our findings show that there is a possible association of HS with CKD. Any signs of CKD should be assessed by a nephrologist as early diagnosis can hopefully prevent further progression.

Hidradenitis Suppurativa: Molecular Etiology, Pathophysiology, and Management-A Systematic Review

Hidradenitis suppurativa is a chronic inflammatory skin condition that affects the hair follicles in areas of the body with apocrine glands. The condition is characterized by recurrent, painful nodules, abscesses, and draining sinuses that can lead to scarring and disfigurement. In this present study, we provide a focused evaluation of recent developments in hidradenitis suppurativa research, including novel therapeutics and promising biomarkers that may facilitate clinical diagnosis and treatment. We conducted a systematic review of controlled trials, randomized controlled trials, meta-analyses, case reports, and Cochrane Review articles in accordance with the PRISMA guidelines. The Cochrane Library, PubMed, EMBASE, and Epistemonikos databases were queried via Title/Abstract screen. Eligibility criteria included the following: (1) has a primary focus on hidradenitis suppurativa, (2) includes measurable outcomes data with robust comparators, (3) details the sample population, (4) English language, and (5) archived as full-text journal articles. A total of 42 eligible articles were selected for review. Qualitative evaluation identified numerous developments in our understanding of the disease's multiple potential etiologies, pathophysiology, and treatment options. It is important for individuals with hidradenitis suppurativa to work closely with a healthcare provider to develop a comprehensive treatment plan that addresses their individual needs and goals. To meet this objective, providers must keep current with developments in the genetic, immunological, microbiological, and environmental factors contributing to the disease's development and progression.

Screening for Diabetes Mellitus in Patients with Hidradenitis Suppurativa—A Monocentric Study in Germany

Hidradenitis suppurativa (HS) is a chronic skin disease that is often associated with metabolic disorders. Diabetes mellitus (DM) is a frequent comorbidity in HS. There is currently no established screening for DM in HS patients. The aim of our study was to identify high-risk groups of HS patients that develop DM and to assess the frequency of different types of DM present in HS patients. To do so, we conducted a monocentric study in 99 patients with HS. All patients underwent detailed clinical and laboratory assessments, including the determination of glycated hemoglobin. Among the 20.2% of patients that presented with DM, type 2 was by far the most prevalent (19 out of 20 patients). Moreover, male gender, age, BMI, Hurley stage, modified Hidradenitis Suppurativa Score (mHSS), DLQI and hypertension all correlated with the glycated hemoglobin levels in the HS patients. In the multivariable analysis, Hurley stage III, older age, and higher BMI were significantly associated with DM. Specifically, patients at Hurley stage III were at a 5.3-fold increased risk of having DM type II compared to patients at earlier Hurley stages. Since many of the HS patients had not been diagnosed, our study reveals shortcomings in the screening for DM and suggest that this should be routinely performed in HS patients at high risk to avoid secondary complications.

Epidemiology and comorbidity of hidradenitis suppurativa in Korea for 17 years: A nationwide population-based cohort study

Hidradenitis suppurativa (HS) is associated with various metabolic and autoimmune diseases. The epidemiology has been analyzed in various studies worldwide. However, epidemiological data on HS for Asian populations are limited. This study aimed to analyze the change in the prevalence and incidence of HS over 17 years in South Korea using the Korean National Health Insurance Service (NHIS) database. This study also evaluated the comorbidities in patients with HS. Population-based data from the NHIS database of Korea were obtained between January 2003 and December 2019. Odds ratios were estimated to determine the association between comorbidities and HS during the study period. Hazard ratios for the risk of incident comorbidities in patients with HS were obtained using the multivariable Cox proportional hazard analysis. This study included 45 511 patients with HS and 910 220 controls matched for age, sex, insurance type, and income level. The incidence rate of HS per 1 000 000 person-years in Korea increased from 11.69 in 2003 to 78.78 in 2019. The annual prevalence per 1 000 000 people also increased from 34.68 in 2003 to 140.10 in 2019, showing a similar trend. Many comorbidities, including atopic, metabolic and end-organ, autoimmune/inflammatory, and psychiatric diseases were associated with HS at baseline. In many diseases, the risk of incident comorbidities in patients with HS was higher than that in controls. The incidence and prevalence of HS in Korea have increased over the past 17 years. Various comorbidities, including allergic diseases, hypertension, diabetes mellitus, dyslipidemia, myocardial infarction, chronic hepatitis and cirrhosis, chronic kidney disease, inflammatory bowel diseases, rheumatoid arthritis, vitamin D deficiency, and psychiatric diseases, were associated with HS. Physicians need to keep in mind and closely monitor these comorbidities in patients with HS.

The Role of Hormones in Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic inflammatory disease manifesting in inverse body regions. In a systematic review, the role of hormones in HS will be presented to better understand the pathomechanisms of HS. The review is based on the PRISMA criteria. Systematic research was carried out using keywords. Subsequently, the data were analyzed based on the clinical response and other relevant information. The main focus of our systematic review was on HS manifestation, exacerbation, sex hormones, antiandrogen therapy, thyroid function, polycystic ovary syndrome, insulin resistance, and adipokines. In HS, there appears to be a dysregulated adipokine release that is shifted towards pro-inflammatory adipokines. Insulin resistance is significantly more common in HS than in healthy patients regardless of BMI, age, and gender. Insulin resistance in HS patients leads to further cardiovascular disease. The mechanism of insulin resistance and role of adipokines should be investigated in future studies to better provide the pathomechanisms of HS. The role of androgens seems to be important in a certain subgroup of female patients. Anti-androgenic therapy can be useful and helpful in some patients. However, further studies are needed to better understand the hormonal relationship in HS.

Comorbid diseases of hidradenitis suppurativa: a 15-year population-based study in Olmsted County, Minnesota, USA

BACKGROUND

Like other chronic, inflammatory skin disorders, hidradenitis suppurativa (HS) is increasingly recognized to be associated with various medical disorders.

OBJECTIVE

Using the Rochester Epidemiology Project (REP), we sought to conduct the first American population-based study examining the association between HS and various comorbid conditions.

METHODS

From the REP database, we identified patients diagnosed with HS from 2003 through 2018 who were residents of Olmsted County, Minnesota, USA, along with age- and gender-matched controls. The frequency of a wide variety of comorbid conditions was compared between the groups.

RESULTS

A total of 1160 patients with HS were identified during the study period. Compared with age- and gender-matched controls, patients with HS had a significantly higher frequency of several medical conditions, including depression, anxiety, hyperlipidemia, acne conglobata, dissecting cellulitis, pilonidal cysts, polycystic ovary syndrome, diabetes, chronic kidney disease, psoriasis, atopic dermatitis, obesity, and disordered substance use, among others.

LIMITATIONS

Our study was limited by its retrospective design.

CONCLUSIONS

Providers caring for patients with HS should consider these results, along with those of similar studies, and obtain a thorough history, comprehensive physical examination, and, potentially, laboratory testing and referral to other specialists.

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.

Cardiovascular Disease-Associated Skin Conditions

According to data from the American Heart Association and the World Health Organization, cardiovascular disease (CVD) is the most frequent cause of premature death. Several inflammatory and non-inflammatory skin diseases have been associated with metabolic syndrome and cardiovascular risk (CVR). Here, we classified these conditions into traditionally CVR-associated and those that have been linked to a lesser degree. Psoriasis and hidradenitis suppurativa are commonly associated with CVD, sharing common inflammatory pathways and a higher prevalence of traditional cardiovascular risk factors. Many other diseases could be associated indirectly – with no common pathogenic features with the atheromatous disease – but share a higher prevalence of standard cardiovascular risk and chronic inflammatory state. This review aims to highlight the associated cardiovascular risk that exists for some dermatologic diseases and sensitize cardiologists, dermatologists, and first care providers to implement risk factor control promptly.

The Role of Nutrition in Immune-Mediated, Inflammatory Skin Disease: A Narrative Review

Immune-mediated inflammatory skin diseases are characterized by a complex multifactorial etiology, in which genetic and environmental factors interact both in genesis and development of the disease. Nutrition is a complex and fascinating scenario, whose pivotal role in induction, exacerbation, or amelioration of several human diseases has already been well documented. However, owing to the complexity of immune-mediated skin disease clinical course and breadth and variability of human nutrition, their correlation still remains an open debate in literature. It is therefore important for dermatologists to be aware about the scientific basis linking nutrition to inflammatory skin diseases such as psoriasis, atopic dermatitis, hidradenitis suppurativa, bullous diseases, vitiligo, and alopecia areata, and whether changes in diet can influence the clinical course of these diseases. The purpose of this narrative review is to address the role of nutrition in immune-mediated inflammatory skin diseases, in light of the most recent and validate knowledge on this topic. Moreover, whether specific dietary modifications could provide meaningful implementation in planning a therapeutic strategy for patients is evaluated, in accordance with regenerative medicine precepts, a healing-oriented medicine that considers the whole person, including all aspects of the lifestyle.

Cumulative Inflammation and HbA1c Levels Correlate with Increased Intima-Media Thickness in Patients with Severe Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that has been associated with a greater risk of metabolic and cardiovascular comorbidities. The aim of this study is to assess cardiovascular risk by means of intima-media thickness (IMT), metabolic syndrome, and other potential biomarkers in patients with severe hidradenitis suppurativa who are candidates for biologic therapy and to explore potentially associated factors. A cross-sectional study was performed. Body mass index (BMI), carotid intima-media thickness (IMT), and blood tests, including glycemic and lipid profile, insulin, vitamin D, and inflammation markers were performed. Fifty patients were included in the study; the male/female ratio was 3:2. The mean age was 38 years, and the mean disease duration was 21.8 years. The mean carotid IMT was 651.39 μm. A positive association of IMT with disease duration, tobacco consumption, and HbA1c levels was observed. HbA1c correlated with the age of onset, hypertension, metabolic syndrome, and glucose levels. Vitamin D levels inversely correlated with the number of areas affected. In conclusion, patients with severe HS present a higher cardiovascular risk, but it is not distributed equally within the patients: Tobacco consumption, inadequate glycemic control, and disease duration could be useful clinical and biochemical markers to identify patients at higher risk.

Diabetes Detection and Prevention in Dermatology

We are currently in the midst of an international epidemic of diabetes mellitus (DM) and prediabetes. The prevalence of DM in the United States is estimated at 9.4% of the population across all ages, while an estimated 1 in 3 Americans (33.9%) has prediabetes. According to the WHO, about 60 million people suffer from diabetes in the European Region. Dermatologists may play an important role in tackling this epidemic via efforts to improve early detection of both diabetes and prediabetes. Dermatologists often treat patients with, or at risk of, diabetes. This includes patients who present with cutaneous manifestations such as acanthosis nigricans, as well as patient populations at increased risk, including those with psoriasis, hidradenitis suppurativa, and polycystic ovarian syndrome. Simple screening guidelines can be used to identify patients at risk, and screening can be performed via a single non-fasting blood test. The diagnosis of prediabetes is a key feature in diabetes prevention, as interventions in this group can markedly reduce progression towards diabetes. In addition to referral to a primary care physician, dermatologists may refer these patients directly to structured behavioral lifestyle intervention programs known as diabetes prevention programs. A significant portion of the population lacks routine care by a primary care physician, and current data indicates need for improvement in diabetes screening and prevention among patient groups such as those with psoriasis. These factors highlight the importance of the dermatologist's role in the detection and prevention of diabetes.

Metabolic syndrome and hidradenitis suppurativa: epidemiological, molecular, and therapeutic aspects

Hidradenitis suppurativa (HS) is a chronic, suppurative condition of the pilosebaceous unit. Patients suffering from HS demonstrate a molecular profile in keeping with a state of systemic inflammation and are often found to fit the criteria for a diagnosis of metabolic syndrome (MetS). In this paper, we review the literature with regards to established data on the prevalence of MetS in HS patients and revise the odds ratio of comorbid disease. Furthermore, we attempt to draw parallels between inflammatory pathways in HS and MetS and evaluate how convergences may explain the risk of comorbid disease, necessitating the need for multidisciplinary care.

Hidradenitis Suppurativa: Where We Are and Where We Are Going

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease primarily affecting apocrine gland-rich areas of the body. It is a multifactorial disease in which genetic and environmental factors play a key role. The primary defect in HS pathophysiology involves follicular occlusion of the folliculopilosebaceous unit, followed by follicular rupture and immune responses. Innate pro-inflammatory cytokines (e.g., IL-1β, and TNF-α); mediators of activated T helper (Th)1 and Th17 cells (e.g., IFN-γ, and IL-17); and effector mechanisms of neutrophilic granulocytes, macrophages, and plasma cells are involved. On the other hand, HS lesions contain anti-inflammatory mediators (e.g., IL-10) and show limited activity of Th22 cells. The inflammatory vicious circle finally results in pain, purulence, tissue destruction, and scarring. HS pathogenesis is still enigmatic, and a valid animal model for HS is currently not available. All these aspects represent a challenge for the development of therapeutic approaches, which are urgently needed for this debilitating disease. Available treatments are limited, mostly off-label, and surgical interventions are often required to achieve remission. In this paper, we provide an overview of the current knowledge surrounding HS, including the diagnosis, pathogenesis, treatments, and existing translational studies.

Evaluation of serum omentin-1 and apelin concentrations in patients with hidradenitis suppurativa

Introduction

Recent studies suggest a role of adipokines in the pathogenesis of hidradenitis suppurativa (HS). Omentin-1 and apelin are two recently identified adipokines that have been involved in the regulation of metabolic and inflammatory responses.

Aim

To investigate serum omentin-1 and apelin levels in patients with HS and to assess their associations with metabolic parameters, disease severity and HS risk.

Material and methods

This case-control study included 139 non-diabetic individuals (78 HS patients and 61 ageand sex-matched controls). Serum concentrations of omentin-1 and apelin and the homeostasis model assessment of insulin resistance (HOMA-IR) were measured in all participants.

Results

Serum omentin-1 concentrations were significantly higher in HS patients compared to controls, whereas apelin serum levels did not significantly differ between both groups. These differences in omentin-1 concentrations remained significant even after adjusting for age, sex, and body mass index (BMI). The results of logistic regression analysis showed that increased omentin-1 plasma levels were an independent risk factor for HS. However, we found no association between serum levels of both omentin-1 and apelin with HS severity.

Conclusions

Our results show that patients with HS have raised omentin-1 serum levels, which are associated with HS risk.

Target molecules for future hidradenitis suppurativa treatment

The registration of the tumour necrosis factor-α inhibitor adalimumab in 2015 was a major step forward in the treatment of hidradenitis suppurativa/acne inversa (HS). However, it soon became evident that the effectiveness of adalimumab in daily practice was highly variable. A significant unmet medical need of HS patients remained, and the search for novel therapeutic targets was intensified. During the 10th European Hidradenitis Suppurativa Foundation (EHSF) e.V. Conference, reknown international HS investigators virtually presented and discussed the published data on these potential target molecules for future HS treatment. This article addresses the most promising molecules currently under investigation from a pathophysiological and clinical point of view. With phase III trials ongoing, the anti- interleukin (IL)-17 biologics bimekizumab and secukinumab are in the most advanced stage of clinical development showing promising results. In addition, targeting IL-1α with bermekimab has shown encouraging results in two clinical trials. Directing treatment at neutrophil recruitment and activation by targeting IL-36 with spesolimab fits well in the pathogenic concept of HS and clinical phase II trial results are pending. In contrast to in situ evidence, Complement 5a (C5a) and C5a receptor blockade have only shown greater clinical benefit in patients with severe HS. Inhibition of Janus kinase (JAK) 1 signalling in HS showed clinical efficacy only in the highest dosage, highlighting that careful surveillance of the balance between safety and efficacy of JAK inhibition is warranted. Overall, clinical efficacies of all novel treatments reported so far are modest. To guide drug development, more and better-defined translational data on the pathogenesis of this severe and enigmatic inflammatory skin disease are required.

Association between Hidradenitis Suppurativa and Inflammatory Arthritis: A Systematic Review and Meta-Analysis

BACKGROUND

Several studies report a high prevalence of inflammatory arthritis among hidradenitis suppurativa (HS) patients.

OBJECTIVES

To study the association between HS and inflammatory arthritis.

METHODS

The systematic review and meta-analysis were performed according to the PRISMA guidelines to identify the association between HS and inflammatory arthritis, spondyloarthritis, ankylosing spondylitis (AS), and rheumatoid arthritis (RA).

RESULTS

Seven studies were entered in the analysis, with 200,361 HS patients and 385,599 controls. Pooled analysis illustrated a significantly increased risk of inflammatory arthritis in HS patients compared to controls (odds ratio [OR] 3.44; 95% confidence interval [CI] 1.92-6.17). There was also a statistically significant association between HS and spondyloarthritis (OR 2.10; 95% CI 1.40-3.15), and between HS and AS (OR 1.89; 95% CI 1.14-3.12). Moreover, pooled analysis showed a statistically significant association between HS and RA (OR 1.96; 95% CI 1.28-2.98).

CONCLUSIONS

Our findings show that HS patients have a 3-fold increased risk of developing inflammatory arthritis. HS patients are specifically at a higher risk for spondyloarthritis, its subtype AS, and RA.

Assessment of Overall and Specific Cancer Risks in Patients With Hidradenitis Suppurativa

Importance

Large population-based studies investigating the risks of overall and specific cancers among patients with hidradenitis suppurativa (HS) are limited.

Objective

To assess the overall and specific cancer risks in patients with HS compared with the risks in patients without HS in the Republic of Korea.

Design, Setting, and Participants

A nationwide population-based cohort study, using the Korean Health Insurance Review and Assessment Service database was conducted over a 2-year period from January 1, 2007, to December 31, 2008. Individuals in the control group who were never diagnosed with HS or cancer during the washout period were randomly extracted and matched by age, sex, index year, and insurance type at a case-control ratio of 1:8, and patients with newly diagnosed HS between January 1, 2009, and December 31, 2017, were included. Follow-up data on incident cancer from January 1, 2009, to December 31, 2018, were included.

Main Outcomes and Measures

The overall and specific cancer incidence rates were calculated per 100 000 person-years in patients with HS and in the matched control cohort. The risk for cancers was assessed by multivariable Cox regression models in patients with HS compared with the matched control cohort.

Results

In total, 22 468 patients with HS and 179 734 matched controls were included in the study. The mean (SD) age was 33.63 (17.61) years and 63.7% of the participants in both groups were male. The adjusted hazard ratio (aHR) of overall cancer in patients with HS was 1.28 (95% CI, 1.15-1.42). Patients with HS had significantly higher risk for Hodgkin lymphoma (aHR, 5.08; 95% CI, 1.21-21.36), oral cavity and pharyngeal cancer (aHR, 3.10; 95% CI, 1.60-6.02), central nervous system cancer (aHR, 2.40; 95% CI, 1.22-4.70), nonmelanoma skin cancer (HR, 2.06; 95% CI, 1.12-3.79), prostate cancer (aHR, 2.05; 95% CI, 1.30-3.24), and colorectal cancer (aHR, 1.45; 95% CI, 1.09-1.93).

Conclusions and Relevance

In this study, HS appeared to be associated with a significantly increased risk of overall cancer as well as several specific cancers.

The Microbiome in Hidradenitis Suppurativa: A Review

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic autoinflammatory skin disease. It is characterised by the development of abscesses and nodules in intertriginous anatomical sites. Whilst it is now recognised as an autoinflammatory condition rather than an infective disease, bacteria are implicated in disease pathogenesis.

METHODS

We performed a search of the literature from inception to 12 August 2020 using the search terms "hidradenitis suppurativa", "Verneuil's disease", "acne inversa", "microbiome", "bacteriology" and "microbiology". Studies were included if they assessed the cutaneous, gut or oral bacteria, bacteriology or microbiome in hidradenitis suppurativa.

RESULTS

Twenty-one studies examining the cutaneous microbiome and two studies examining the gastrointestinal microbiome in HS were identified. No studies examining the oral microbiome in HS were identified. A total of 972 patients and 46 healthy controls were included across studies examining the cutaneous microbiome. A total of 100 patients and 36 controls were included across both gut microbiome studies. Coagulase-negative Staphylococcus, anaerobes such as Porphyromonas and Prevotella, and Staphylococcus aureus species were commonly encountered organisms across the included cutaneous microbiome studies. The studies examining the gut microbiome were limited, with one small study demonstrating an alteration in the gut microbiome composition compared to controls. The other study found no alteration to the gut microbiome in patients with HS compared to those with inflammatory bowel disease (IBD) and HS, and IBD and/or psoriasis.

CONCLUSION

Research should be undertaken into the oral microbiome in HS. Further research should be undertaken examining the cutaneous and gut microbiome in HS, and its relationship with documented co-morbidities. Additionally, metagenomics-focused studies may help identify the relationship between microorganisms and host, and this may shed light on new pathways of disease pathogenesis. This may help identify potential future therapeutic targets.

Comorbidity screening in hidradenitis suppurativa: Evidence-based recommendations from the US and Canadian Hidradenitis Suppurativa Foundations

Background:

Hidradenitis suppurativa (HS) is associated with comorbidities that contribute to poor health, impaired life quality, and mortality risk.

Objective:

To provide evidence-based screening recommendations for comorbidities linked to HS.

Methods:

Systematic reviews were performed to summarize evidence on the prevalence and incidence of 30 comorbidities in patients with HS relative to the general population. The screening recommendation for each comorbidity was informed by the consistency and quality of existing studies, disease prevalence, and magnitude of association, as well as benefits, harms, and feasibility of screening. The level of evidence and strength of corresponding screening recommendation were graded by using the Strength of Recommendation Taxonomy (SORT) criteria.

Results:

Screening is recommended for the following comorbidities: acne, dissecting cellulitis of the scalp, pilonidal disease, pyoderma gangrenosum, depression, generalized anxiety disorder, suicide, smoking, substance use disorder, polycystic ovary syndrome, obesity, dyslipidemia, diabetes mellitus, metabolic syndrome, hypertension, cardiovascular disease, inflammatory bowel disease, spondyloarthritis, and sexual dysfunction. It is also recommended to screen patients with Down syndrome for HS. The decision to screen for specific comorbidities may vary with patient risk factors. The role of the dermatologist in screening varies according to comorbidity.

Limitations:

Screening recommendations represent one component of a comprehensive care strategy.

Conclusions:

Dermatologists should support screening efforts to identify comorbid conditions in HS.

Aetiology and pathogenesis of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disorder. Patients develop inflamed nodules and abscesses and, at later stages of disease, epithelialized tunnels and scars in skinfolds of axillary, inguinal, gluteal and perianal areas. Quality of life is affected due to severe pain, purulent secretion, restricted mobility and systemic involvement. Genetics and lifestyle factors including smoking and obesity contribute to the development of HS. These factors lead to microbiome alteration, subclinical inflammation around the terminal hair follicles, and infundibular hyperkeratosis, resulting in plugging and rupture of the follicles. Cell-damage-associated molecules and propagating bacteria trigger inflammation and lead to massive immune cell infiltration that clinically manifests as inflamed nodules and abscesses. The immune system plays a key role also in the progression and chronification of skin alterations. Innate proinflammatory cytokines (e.g. interleukin-1β and tumour necrosis factor-α), mediators of activated T helper (Th)1 and Th17 cells (e.g. interleukin-17 and interferon-γ), and effector mechanisms of neutrophilic granulocytes, macrophages and plasma cells are involved. Simultaneously, skin lesions contain anti-inflammatory mediators (e.g. interleukin-10) and show limited activity of Th22 and regulatory T cells. The inflammatory vicious circle finally results in pain, purulence, tissue destruction and scarring. Chronic inflammation in patients with HS is also frequently detected in organs other than the skin, as indicated by their comorbidities. All these aspects represent a challenge for the development of therapeutic approaches, which are urgently needed for this debilitating disease. This scholarly review focuses on the causes and pathogenetic mechanisms of HS and the potential therapeutic value of this knowledge.

The epidemiology of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease defined clinically by multiple, painful inflammatory lesions occurring predominantly in flexural sites. Onset is typically soon after puberty; however, it remains unknown whether the menopause induces remission. In North American and European patients with HS the female-to-male ratio is approximately 3 : 1 but the ratio is 1 : 2 in South Korean patients. It may be that some elements of HS epidemiology cannot be generalized across all populations. Elements of HS epidemiology in the USA and Europe are well established, including strong associations with obesity and smoking, which may increase disease severity. There are associations between HS and other cardiovascular disease (CVD) risk factors, including type 2 diabetes and metabolic syndrome. People with HS have double the risk of death from CVD compared with those without HS and 1·5 times the risk compared with patients with psoriasis. Depression and anxiety are associated with HS and completed suicide rates in those with HS are more than double the rates in controls. Associations exist between HS and other chronic inflammatory conditions, particularly inflammatory bowel disease and inflammatory arthritis. Case-control studies demonstrate associations with pilonidal sinus, polycystic ovary syndrome, Down syndrome, obstructive sleep apnoea and pyoderma gangrenosum. Population-based studies using routinely collected healthcare data from the USA estimate a prevalence of 0·1%, suggesting HS is relatively uncommon. European studies include undiagnosed patients and typically estimate prevalence of 1% or more, suggesting a common condition. Resolving the controversy surrounding a greater than 10-fold difference in HS prevalence estimates remains a high priority.

Atherogenic index of plasma is associated with the severity of Hidradenitis Suppurativa: a case-control study

Background

Hidradenitis suppurativa (HS) is a chronic inflammatory disease associated with several comorbidities and vascular risk factors, such as dyslipidemia. The present study aimed to assess the possible associations between the lipid profile and atherogenic indexes and the severity of HS.

Methods

This case-control study enrolled 78 HS patients and 62 healthy controls. Classic lipid profile and lipoprotein ratios, including the atherogenic index of plasma (AIP), were evaluated. The severity of HS was measured by the HS Physician Global Assessment (PGA).

Results

HS-patients had lower serum total cholesterol and HDL-C levels and higher AIP than the control group. AIP was positively correlated to BMI, waist circumference, systolic and diastolic blood pressure, LDL-C, triglycerides, non-HDL-C, ApoB, HOMA, and hs-CRP and negatively to HDL-C and ApoA1. For the overall lipid profile, only AIP was related to a more severe HS (PGA ≥ 3) after controlling for age, sex, BMI, insulin resistance (IR), active smoking, and statin use (r = 0.268; p = 0.023). Multiple logistic regression adjusted for age, sex, BMI, IR, smoking status and statin use, showed that AIP ≥ 0.11 was significantly associated with the severity of HS (OR, 4.38; CI 95%, 1.09–17.50; p = 0.037).

Conclusions

In conclusion, these results showed that AIP is significantly and independently associated with HS severity.

Hidradenitis suppurativa epidemiology: from the first Italian registry in 2009 to the most recent epidemiology updates - Italian Registry Hidradenitis Suppurativa project 2

BACKGROUND

The incidence of hidradenitis suppurativa (HS) is still not fully established with only a few studies reporting its estimates. Prevalence estimates range from 5:10 000 to 4:100. These extremely large variations could be explained by a combination of factors, including different selection procedures, different diagnostic criteria, and variations in the sex and age distribution of the examined samples.

OBJECTIVES

To analyze variations between two consecutive Italian Registries on HS.

METHODS

Data obtained from the second Italian Registry on HS, named 'Italian Registry Hidradenitis Suppurativa (IRHIS) Project 2', are compared to the previous first Italian registry on HS.

RESULTS

Data on 944 patients are reported. The more relevant aspects that characterize IRHIS 2 project, in comparison with the previous first Italian Registry on HS, are as follows: (i) the total number of patients, about fourfold higher; (ii) a more uniform national geographic distribution of the patient population; (iii) a larger number of dermatology units involved; (iv) a larger number of items considered in the data collection; (v) 6 years of difference between the onset of the two registries (2009-2013 vs. 2015-2019). Comparing data of the two registries, there are no statistically significant differences in terms of age at the time of the visit, gender, BMI, smoking habits, age at onset and age at first diagnosis by physician. Interestingly, the mean Sartorius score in the IRHIS project 2 (58.8) was significantly lower compared to the first Italian Registry (78.4).

CONCLUSIONS

The importance of the registries, at both national and international levels, in collecting useful real-life data is confirmed by these two Italian projects.

Circulating levels of adiponectin, leptin, resistin and visfatin in non-diabetics patients with hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disease associated with insulin resistance (IR), metabolic syndrome and increased cardiovascular risk. Adipokines are biologically active, pleotropic molecules which have been involved in the development of IR and in the pathogenesis of several chronic inflammatory conditions. The aim of the present study was to analyze serum concentrations of adiponectin, leptin, resistin and visfatin in patients with HS, and investigate their possible associations with IR, HS risk and disease severity. This case-control study enrolled 137 non-diabetic individuals (76 HS-patients and 61 age and sex-matched controls). Serum concentrations of adiponectin, leptin, resistin and visfatin, and the homeostasis model assessment of IR (HOMA-IR) were measured in all the participants. Serum adiponectin concentrations were found to be significantly lower, and leptin, resistin and visfatin levels were significantly higher in HS-patients than in controls. These differences remained significant even after adjusting for age, sex and body mass index, except for leptin. In a multivariate regression analysis, HOMA-IR was inversely correlated with adiponectin and positively associated with resistin levels. Furthermore, serum levels of resistin and visfatin were independently associated with HS risk. However, we found no association between serum levels of adipokines and HS severity. Our results suggest that reduced adiponectin and increased resistin serum levels may be surrogate biomarkers for IR in patients with HS. Moreover, resistin and visfatin might be independent risk factors for the development of HS.

Demographic and Clinical Features of Hidradenitis Suppurativa in Turkey

Background

The literature contains conflicting reports on the epidemiology and frequency of hidradenitis suppurativa (HS), a chronic, recurrent inflammatory disease of the apocrine glands.

Objective

To evaluate the clinical and demographic characteristics of HS cases in Turkey and investigate the similarities with world epidemiology.

Method

The records of 208 patients that presented to our polyclinics and were diagnosed with HS between June 2012 and July 2017 were retrospectively evaluated.

Results

Of the cases, 68.3% were male and 31.7% were female. Of the patients, 75.5% had no family history of HS, 60.6% were smokers, 39.4% were aged 20-29 years, and 36.1% were aged 30-39 years. The most commonly involved regions were the axilla (62%), groin (50.5%), and gluteus (15.9%). According to univariate analyses, male patients had higher disease stages than females (odds ratio=1.67). The patients with groin involvement, high body mass index (BMI), and low education level (0-8 years) had higher risk of severe disease stage (odds ratio=1.63, 8.91, and 1.51, respectively). The most commonly used treatment was oral antibiotics in Hurley stages I and II, and surgical intervention in Hurley III. In all 3 Hurley stages, clavulanic acid–amoxicillin combination was the mostly used systemic antibiotic (41.8%, 43.2%, and 47.8%, respectively).

Conclusions

This is the first epidemiological study on HS in the Turkish population, where HS shows male predominance. Male gender, low education level, absence of acne, high BMI, and groin involvement were associated with severe disease stages. Determining associated comorbidities and possible risk factors is important in progression and prevention of the disease.

Comorbidities of hidradenitis suppurativa: A review of the literature

Background

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that affects the follicular portion of folliculopilosebaceous units. It causes painful nodules, abscesses, and draining sinus tracts throughout multiple regions of the body. HS primarily affects women; the overall HS prevalence in women is three times that in men. Although cutaneous disease itself causes substantial morbidity, recent evidence has shown that HS is a systemic inflammatory disease with multiple associated comorbidities.

Objective

A review of the literature was conducted to elucidate existing information on this topic to assist in clinical decision-making for dermatologists.

Methods

A review of the literature using the PubMed database was conducted with the search term "hidradenitis suppurativa comorbidities". The search was conducted from March 3, 2019 to March 20, 2019, and yielded 55 articles, case reports, and reviews.

Results

Metabolic and cardiovascular comorbidities were the most commonly associated with HS. HS has a significant comorbidity burden beyond the skin, including metabolic, cardiovascular, endocrine, gastrointestinal, rheumatologic, and psychiatric disorders, which collectively decrease the quality of life of patients.

Conclusions

Dermatologists should be aware of these associations to encourage appropriate screening and referral for management of these disorders.