Bacteriology of hidradenitis suppurativa exacerbations and deep tissue cultures obtained during carbon dioxide laser treatment

Unraveling the Skin Microbiome in Hidradenitis Suppurativa: Implications for Treatment and Disease Progression

Background: Hidradenitis suppurativa (HS) is a chronic, disabling, and disfiguring inflammatory disease with a complex, incompletely elucidated pathogenesis. The role of skin dysbiosis in the development and progression of HS has not yet been clarified. Methods: We performed an observational, prospective culture-based study that included 40 HS patients and analyzed the bacterial load and diversity in HS skin lesions, their correlation with disease severity, and several host and environmental factors. Additionally, we investigated the prevalence of antibiotic resistance and determined the resistance profile of bacterial strains isolated from chronic HS lesions. Results: An impressive number and diversity of bacterial strains were isolated from both superficial and deep HS lesions. 201 aerobic and anaerobic bacterial strains were isolated, polymicrobial growth being detected in the majority of samples. The most frequently isolated bacteria were Staphylococcus epidermidis, Staphylococcus aureus, Staphylococcus lugdunensis, Peptoniphilus spp., and Enterococcus faecalis in superficial lesions and Staphylococcus epidermidis, Staphylococcus aureus, and Corynebacterium tuberculostearicum in deep lesions. A significantly higher bacterial density and diversity was found in male patients, regardless of the affected area and in patients with severe HS. The proportion of bacterial strains resistant to antibiotics was lower in our study (8.95%) compared to the previously reported data. Conclusions: Our findings indicate dysbiosis as a key player in the initiation and maintenance of the inflammatory process in HS. Further large-scale, prospective studies are required to comprehensively characterize the microbiological landscape of HS and shed light on its contribution in the pathogenesis of the disease.

Microbiome Perturbations in Hidradenitis Suppurativa

Skin and gut microbiome perturbations may play a role in hidradenitis suppurativa (HS) pathogenesis. Emerging microbiome research has established the complex roles of the skin and gut microbiomes in health maintenance and disease. Perturbations in the HS skin microbiome have been shown to correlate with HS disease severity. HS gut microbiome characterization studies point to a trend in decreased microbial diversity associated with HS. Future research efforts examining microbiome perturbations and their functional implications longitudinally and in the setting of interventions are needed to build on this foundational knowledge.

Roles of skin microbiota in hidradenitis suppurativa: insights from a two-sample mendelian randomization analysis

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease associated with unique lesional dysbiotic features. However, the role of the microbiology in the pathogenesis of HS remains in dispute. We aimed to conduct a two-sample Mendelian randomization study to investigate the relationship between skin microbiota and HS. A two-sample Mendelian randomization study was performed using the summary statistics of skin microbiota from summary GWAS data of the European descent from two cross-sectional, population-based German cohorts, KORA FF4 (n = 324) and PopGen (n = 273). The summary statistics of hidradenitis suppurativa were obtained from the FinnGen DF10 (1,070 cases and 394,105 controls). Inverse variance weighted (IVW), MR-Egger regression, weighted median, simple mode, weighted mode, and MRPRESSO were used to examine the causal association between skin microbiota and hidradenitis suppurativa. Cochran's Q statistics were used to quantify the heterogeneity of instrumental variables. Our study suggested that genus Corynebacterium in dry skin is significantly associated with HS after false discovery rate (FDR) correction (odds ratio (OR) = 1.04, 95% confidence interval (CI): 1.02-1.06, P = 0.0002, FDR adjusted P = 0.035). Additionally, we found genus Micrococcus in moist skin (OR = 1.10, 95% CI: 1.03-1.18, P = 0.0060, FDR adjusted P = 0.360), species Streptococcus salivarius in dry skin (OR = 1.03, 95% CI: 1.01-1.05, P = 0.0070, FDR adjusted P = 0.360), and species Propionibacterium granulosum (OR = 1.02, 95% CI: 1.00-1.04, P = 0.0460, FDR adjusted P = 0.970) are potentially associated with HS before FDR adjustment. No evidence of the effect in the reverse direction for HS on skin microbial features. This two-sample Mendelian randomization study found that genus Corynebacterium was causally associated with HS. Further studies are needed to clarify the protective effect of prebiotics, probiotics or microbiome transplants on HS.

Microbial Colonization and Antibiotic Resistance Profiles in Chronic Wounds: A Comparative Study of Hidradenitis Suppurativa and Venous Ulcers

Background/Objectives: Chronic wounds, including hidradenitis suppurativa (HS) and venous ulcers (VU), are commonly associated with complex microbial communities that may influence wound healing and treatment outcomes. Understanding microbial diversity and antibiotic resistance patterns is essential in order to optimize therapeutic strategies. This study aimed to investigate the microbial populations and antibiotic resistance profiles in HS and VU patients, comparing the prevalence of common pathogens and their antimicrobial resistance profiles. Methods: We conducted a cross-sectional analysis that included a total of 112 individuals (24 with the diagnosis of hidradenitis suppurativa and 88 diagnosed with venous ulcer). Wound swabs were cultured to identify bacterial species, and antibiotic resistance was assessed using a standard panel of antibiotics. Prevalence rates of key pathogens, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis, were compared between the two groups. Resistance patterns were analyzed using statistical methods to identify significant differences. Results: Staphylococcus aureus was the most common pathogen in both groups (45.8% in HS; 38.6% in VU), with a notable prevalence of methicillin-resistant S. aureus (MRSA). Pseudomonas aeruginosa was exclusively identified in VU patients (27.3%), while beta-hemolytic Streptococcus and Corynebacterium amycolatum were identified in HS cases only. Antibiotic resistance was moderate, notably in S. aureus and Proteus mirabilis, while one case of multidrug-resistant Pseudomonas aeruginosa was identified. Conclusions: This study highlights the distinctive microbial profiles and antibiotic resistance patterns in HS and VU chronic wounds. The predominance of S. aureus in both groups underscores the need for targeted therapies, while the absence of P. aeruginosa in HS wounds and the higher prevalence of other species emphasizes wound-specific microbial variations. These findings underscore the importance of personalized treatment strategies and continuous surveillance of antimicrobial resistance.

Phage therapy for hidradenitis suppurativa: a unique challenge and possible opportunity for personalized treatment of a complex, inflammatory disease

Phage therapy is an emerging antimicrobial treatment for critical multidrug-resistant pathogens. In this review, the specific potential and challenges of phage therapy for patients with hidradenitis suppurativa (HS) are discussed. This represents a unique challenge as HS is a chronic inflammatory disease, but presenting with acute exacerbations, which have an enormous negative impact on patient's quality of life. The therapeutic arsenal for HS has expanded in the past decade, for example, with adalimumab and several other biologicals that are currently under investigation. However, treatment of HS remains challenging for dermatologists because there are individuals who do not respond to any classes of the current treatment options when used for a first or second time. Furthermore, after several courses of treatment, a patient may lose their response to therapy, meaning long-term use is not always an option. Culturing studies and 16S ribosomal RNA profiling highlight the complex polymicrobial nature of HS lesions. Despite the detection of various bacterial species in lesion samples, several key pathogens, including Staphylococcus, Corynebacterium and Streptococcus, may be potential targets for phage therapy. Using phage therapy for the treatment of a chronic inflammatory disease could potentially provide new insights into the role of bacteria and the immune system in HS development. In addition, it is possible more details on the immunomodulatory effects of phages may come to light.

Skin and Gut Microbiome in Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic skin disease that significantly impairs the quality of life of affected individuals. The disease is characterized by persistent purulent lesions in specific anatomical areas, and its pathophysiology involves multiple factors, including inflammation, genetics, the microbiome, and environmental components. Recent research suggests a potential role for pathogenic bacteria in HS, highlighting the importance of the communication between the human host and the microbiome in maintaining homeostasis and immune system reactivity. However, the exact mechanisms underlying the gut-skin microbial interactions in HS remain unclear. This systematic review aims to examine the existing literature on the differences in skin and gut microbiome composition between HS patients and healthy controls. The review identifies methodological inconsistencies and calls for further research to elucidate the microbiome's role in HS pathogenesis and to explore new therapeutic interventions. The review highlights the need for advancements in microbiome research methodologies, such as metataxonomics and metagenomics, to improve our understanding of the microbiota's impact on health and disease.

Consistency of Bacterial Triggers in the Pathogenesis of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is an inflammatory skin disease whose pathogenesis remains poorly defined. Over the past decades, the bacterial role in HS patients has been a focus of research. According to the literature, the HS skin (and probably gut) bacterial composition is different to that of healthy controls. To date, a key question is whether compositional changes in the microbial populations are responsible for the development of HS (primum movens), or only secondarily reflect the ongoing inflammatory process. The great diversity of methodologies that have been used to study microbial role in HS have led to an accumulation of conflicting results. Thus, in view of these considerations, the aim of this article is to provide the reader with an overview about different hypotheses proposed to explain the bacterial role in HS pathogenesis.

Antibiotic Treatment in End Stage Cancer Patients; Advantages and Disadvantages

Aim:

In this study our aim was to elucidate whether advanced cancer patients benefit from antibiotic treatment in the last days of life in addition to reviewing the relevant costs and effects.

Materials And Methods:

We reviewed medical records from 100 end-stage cancer patients and their antibiotic use during the hospitalization in Imam Khomeini hospital. Patient’s medical records were analyzed retrospectively for cause and periodicity of infections, fever, increase in acute phase proteins, cultures, type and cost of antibiotic.

Results:

Microorganisms were found in only 29 patients (29%) and the most microorganism among the patients was E. coli (6%). About 78% of the patients had clinical symptoms. The highest dose of antibiotics was related to Ceftriaxone (40.2%) and in the second place was Metronidazole (34.7%) and the lowest dose was related to Levofloxacin, Gentamycin and Colistin (1.4%). Fifty-one patients (71%) did not have any side effects due to antibiotics. The most common side effect of antibiotics among patients was skin rash (12.5%). The average estimated cost for antibiotic use was 7 935 540 Rials (24.4 dollars).

Conclusion:

Prescription of antibiotics was not effective in symptom control in advanced cancer patients. The cost of using antibiotics during hospitalization is very high and also the risk of developing resistant pathogens during admission should be considered. Antibiotic side effects also occur in patients, causing more harm to the patient at the end of life. Therefore, the benefits of antibiotic advice in this time is less than its negative effects.

Hidradenitis Suppurativa in Patients with HIV: A Scoping Review

Hidradenitis suppurativa (HS) is a chronic, debilitating skin disease of the apocrine glands. Bibliographic search revealed few studies concerning the association between HS and human immunodeficiency virus (HIV). To assess this link, we performed a systematic review of the current knowledge through a careful analysis of the relevant and authoritative medical literature in the field. Results showed that people with HIV are particularly susceptible to developing HS with the characteristic involvement of atypical sites, such as face or thighs, due to HIV-related immunosuppression. Based on the pathogenesis of both conditions and according to our review, we suggest that HIV screening should be routinely performed in suspected cases while monitoring and integrated approach in management are mandatory in the management of HIV-positive patients with HS.

Characteristics of the Skin Microbiome in Selected Dermatological Conditions: A Narrative Review

The skin is the largest and outermost organ of the human body. The microbial diversity of the skin can be influenced by several variable factors such as physiological state, lifestyle, and geographical locations. Recent years have seen increased interest in research aiming at an improved understanding of the relationship between the human microbiota and several diseases. Albeit understudied, interesting correlations between the skin microbiota and several dermatological conditions have been observed. Studies have shown that a decrease or increase in the abundance of certain microbial communities can be implicated in several dermatological pathologies. This narrative review (i) examines the role of the skin microbiota in the maintenance of skin homeostasis and health, (ii) provides examples on how some common skin diseases (acne inversa, candidiasis, psoriasis) are associated with the dysbiosis of microbial communities, and (iii) describes how recent research approaches used in skin microbiome studies may lead to improved, more sensitive diagnostics and individual therapeutics in the foreseeable future.

Microbial Isolates and Association with Disease Severity and Quality of Life in Individuals with Hidradenitis Suppurativa: An Observational Study

Introduction

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by recurrent nodules, abscesses, and sinus tracts, resulting in scarring. Patients suffer significantly impacted quality of life (QoL), manifested by anxiety and depression. We describe microbial isolates identified from active sites in adults with HS, and explore associations between organisms isolated, disease severity, and QoL.

Methods

Observational study over 2 years. Assessment was made of disease severity using the Hurley staging score and of QoL scores, and subjective assessment. Wound swab samples were obtained from sites of active disease. Descriptive summary statistics and tests of significance were used to analyse the data.

Results

Two hundred and twelve patients participated, resulting in 352 episodes, and 501 lesion swab samples. 54% were female and 59% were obese, median age of 37 years. A lower proportion of Gram-negative organisms and more staphylococcal and streptococcal organisms were isolated from sites of disease in individuals with stage 3 disease compared to those with stage 1-2 disease (p = 0.001). We found no association between microbial isolation and QoL.

Discussion/Conclusions

Hurley stage 3 disease is associated with more infected lesions than Hurley stage 1-2 disease, but the QoL experienced by patients with HS is determined by factors other than infection.

The Bacteriology of Skin Lesions in Patients with Hidradenitis Suppurativa Is Associated with Previous Antibiotic Treatment in the Community Setting: A Referral Center Experience

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic skin disease characterized by inflammatory nodules and abscesses. The pathogenic role of bacteria is not fully understood. As the diagnosis is usually delayed, patients are often treated with several lines of antibiotics in a nonstandardized fashion. The aim of the study was to investigate and compare the bacteriology of active HS lesions in patients treated or not treated with antibiotics in the community setting before referral to a dedicated HS clinic.

METHODS

Purulent skin lesions of patients with HS referred to the HS Clinic of Rabin Medical Center in 2009-2020 were cultured. Data were collected from the patients' medical files and microbiology reports. The correlation between the location of the skin lesion and the bacteriologic profile was analyzed, and the effects of previous antibiotic treatment on the bacteriologic profile of the lesions and susceptibility patterns of the cultured bacteria were evaluated.

RESULTS

Pus (or tissue) from inflammatory lesions of 97 patients with HS was cultured. Mean (SD) patient age was 39.5 (13.0) years, and mean delay in diagnosis was 7.3 (8.3) years. Most patients (57.7%) had dominant involvement of one location, with the most active lesions concentrated in the genitalia, gluteal/perineal area, and axilla. Enterobacterales species were the most frequent isolates detected in all locations except the face and scalp. Seventy-eight patients (80.4%) had been treated in the community setting prior to referral with a median (range) of 2 (1-8) lines of antibiotics. The most commonly prescribed antibiotics were amoxicillin/clavulanate (22.0%), doxycycline/minocycline (16.8%), clindamycin (16.2%; monotherapy 8.1%, clindamycin with rifampicin 8.1%), and cephalexin (13.9%). Compared to the previously untreated patients, cultures of lesions from the previously treated patients yielded a higher percentage of gram-negative Enterobacterales (the most common isolates in this group) (31.3% vs. 10.3%) and a significantly higher median number of isolates per culture (2 vs. 1, p < 0.0001). Gram-positive bacteria, usually considered contaminants (mainly coagulase-negative staphylococci) accounted for 31.0% of the isolates in the previously treated group. Susceptibility testing for the entire cohort revealed 100% bacterial sensitivity to ciprofloxacin. Staphylococcus spp. were 100% sensitive to rifampicin. Both gram-positive and gram-negative bacteria had high sensitivity to trimethoprim and sulfamethoxazole.

CONCLUSION

Nonstandardized antibiotic treatment of HS in the community setting can skew the microbiology of skin lesions toward gram-negative bacteria. Therefore, treatment with trimethoprim and sulfamethoxazole or ciprofloxacin, either alone or combined with rifampicin, may be considered.

Hidradenitis Suppurativa: Host-Microbe and Immune Pathogenesis Underlie Important Future Directions

Hidradenitis suppurativa (HS) is an inflammatory disease of the skin with a chronic, relapsing-remitting course. The pathogenesis of the disease is poorly understood and involves multiple factors, including genetics, environment, host-microbe interactions, and immune dysregulation. In particular, the composition of the cutaneous microbiome shifts as the disease progresses, although it is unclear whether this is a primary or secondary process. Trials with immunomodulatory therapy elucidate the role of specific immune pathways and cytokine signaling in disease mechanism, such as TNF-α, IL-1β, IL-12, IL-17, IL-23, and complement. Future studies should continue examining the causes of and contributing factors to microbial changes and immune dysregulation in HS pathogenesis.

Yin and Yang: A disrupted skin microbiome and an aberrant host immune response in hidradenitis suppurativa

The skin microbiome plays an important role in maintaining skin homeostasis by controlling inflammation, providing immune education and maintaining host defense. However, in many inflammatory skin disorders the skin microbiome is disrupted. This dysbiotic community may contribute to disease initiation or exacerbation through the induction of aberrant immune responses in the absence of infection. Hidradenitis suppurativa (HS) is a complex, multifaceted disease involving the skin, innate and adaptive immunity, microbiota and environmental stimuli. Herein, we discuss the current state of HS skin microbiome research and how microbiome components may activate pattern recognition receptor (PRR) pathways, metabolite sensing pathways and antigenic receptors to drive antimicrobial peptide, cytokine, miRNA and adaptive immune cell responses in HS. We highlight the major open questions that remain to be addressed and how antibiotic therapies for HS likely influence both microbial burden and inflammation. Ultimately, we hypothesize that the two-way communication between the skin microbiome and host immune response in HS skin generates a chronic positive feed-forward loop that perpetuates chronic inflammation, tissue destruction and disease exacerbation.

Identifying key components and therapeutic targets of the immune system in hidradenitis suppurativa with an emphasis on neutrophils

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent and debilitating skin disease of the hair follicle unit that typically develops after puberty. The disorder is characterized by comedones, painful inflammatory nodules, abscesses, dermal tunnels and scarring, with a predilection for intertriginous areas of the body (axillae, inguinal and anogenital regions). Recruitment of neutrophils to HS lesion sites may play an essential role in the development of the painful inflammatory nodules and abscesses that characterize the disease. This is a review of the major mediators involved in the recruitment of neutrophils to sites of active inflammation, including bacterial components (endotoxins, exotoxins, capsule fragments, etc.), the complement pathway anaphylatoxins C3a and C5a, tumour necrosis factor-alpha, interleukin (IL)-17, IL-8 (CXCL8), IL-36, IL-1, lipocalin-2, leukotriene B4, platelet-activating factor, kallikreins, matrix metalloproteinases, and myeloperoxidase inhibitors. Pharmacological manipulation of the various pathways involved in the process of neutrophil recruitment and activation could allow for successful control and stabilization of HS lesions and the remission of active, severe flares.

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.

Staphylococcus aureus Carriage in Hidradenitis Suppurativa: Impact on Response to Adalimumab

BACKGROUND

Several patients with hidradenitis suppurativa (HS) present flare-ups during treatment with adalimumab (ADA), the cause of which is not clear. ADA is the only FDA-approved biologic for the therapy of moderate-to-severe HS. A previous study of our group has shown that Staphylococcus aureus stimulation of whole blood affects the production of human β-defensin 2 and modulates HS severity. It is, therefore, hypothesized, that carriage of S. aureus may drive HS flare-ups.

OBJECTIVE

To explore the association between carriage of S. aureus and loss of response to ADA.

PATIENTS AND METHODS

Among patients with moderate-to-severe HS without carriage of S. aureus at start of treatment with ADA, we investigated for carriage of S. aureus from the nares when flare-ups occurred. Flare-ups were pre-defined as at least 25% increase of inflammatory lesions (sum of inflammatory nodules and abscesses) from baseline. Samplings were also done after completion of 12 weeks of ADA treatment from all patients who did not present flare-ups. Clinical response to ADA was assessed by the HS Clinical Response score (HiSCR).

RESULTS

Thirty-nine patients were studied; 24 with Hurley II stage HS and 15 with Hurley III stage HS. Twenty-nine patients achieved HiSCR after 12 weeks of treatment without any flare-ups; 10 patients had flare-ups and failed HiSCR. Three (10.3%) and 5 (50%) patients, respectively, had nasal carriage of S. aureus (odds ratio 8.67; 95% CI 1.54-48.49; p = 0.014). Among 32 patients reaching follow-up week 48, 20 patients achieved HiSCR and 12 had flare-ups leading to ADA failure; 2 (10%) and 5 (41.7%) patients, respectively, had positive culture for S. aureus (odds ratio 6.42; 95% CI 1.00-41.20; p = 0.05).

CONCLUSION

Nasal carriage of S. aureus may be associated with loss of response to ADA. Findings need confirmation in larger series of patients.

Cytokine Pathways and Investigational Target Therapies in Hidradenitis Suppurativa

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting areas with a high density of apocrine glands and characterized by subcutaneous nodules that may evolve into fistulas with pus secretion. Methods: The aim of this review is to investigate all current knowledge on cytokine regulation in the pathogenesis of HS. A systematic literature research using the words “cytokine”, “interleukin”, “pathway”, and “hidradenitis suppurativa” was performed in PubMed/Medline and Scopus/Embase databases. A search of the clinicaltrials.gov website for interventional recruiting and completed trials including the term “hidradenitis suppurativa” was also performed up to August 2020. We will discuss the pathogenetic role of various cytokines in HS and potential therapeutic targets for this debilitating disease. Results: The pathophysiology underlying this complex condition has not been clearly defined. An upregulation of various cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-1, IL-17, IL-23, and other molecules seems to be related to this inflammatory condition. Various cells, such as lymphocytes T Helper 1 and 17 and keratinocytes seem to be involved in the genesis of this condition. Conclusions: Several future studies and clinical trials are necessary in order to have new knowledge about HS and to properly treat this complex condition.

A systematic review and critical appraisal of metagenomic and culture studies in hidradenitis suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic inflammatory skin disease with still largely unknown pathogenesis. While infectious organisms have been identified in lesions of the disease since the 1980s, questions remain over the role that bacteria and microbiome play. Recent studies using 16S ribosomal RNA gene sequencing and larger culture-based studies have begun to paint a clearer picture of the microbial world of HS. With this systematic review, we summarize all the work that has been done to date in HS bacteriology, analyse potential pitfalls and limitations of the current studies, and address future directions of investigation. This systematic review attempted to collate and analyse all bacteriology studies done to date. This review was prospectively registered with PROSPERO (1670769) performed in line with the PRISMA checklist. Twenty two studies were identified comprising 862 individual HS patients for culture studies and 206 HS patients for 16S rRNA gene sequencing studies. Methodology tended to be varied, with different sampling, culturing and sequencing methods as well as amount of analysis and stratification of patients. Bacteria identified as elevated in HS lesions in sequencing studies as well as grown from HS lesions in culture studies are identified and discussed. These primarily included the anerobic Gram-negative bacilli Prevotella, Porphyromonas and Fusibacterium, the Gram-positive bacilli Corynebacterium, and the Gram-positive cocci Staphylococcus, Streptococcus and Parvimonas. Potential interactions, as well as work in other disease models with related bacteria are also discussed. Areas of further investigation include in vitro studies of interactions between bacteria and keratinocytes, gut and oral microbiome studies and deep sequencing studies for virulence and phage factors.

Irrelevance of Panton-Valentine leukocidin in hidradenitis suppurativa: results from a pilot, observational study

Panton-Valentine leukocidin (PVL) appears to be a virulence factor which, among others, can exacerbate the pathogenicity of Staphylococcus aureus infections, especially inducing severe necrotic, deep-seated skin infections, abscesses, and recurrences. These peculiarities have some overlaps with hidradenitis suppurativa (HS). Our main aim was to assess if S. aureus producing PVL could have some role in influencing clinical features and/or course of HS, specifically in the suppuration and recurrence of lesions. This pilot, mono-centric, observational study included all adult subjects affected with HS consecutively referring to our HS clinic over a 3-month period. Clinically evident suppuration and at least 2 weeks wash out from any antibiotic were the main inclusion criteria. Purulent material from HS skin lesions was collected with swabs in order to isolate micro-organisms, with specific regard to S. aureus. Detection of PVL was performed by real-time quantitative PCR (RT-qPCR). We also analyzed purulent material from suppurative skin lesions other than HS, as a control. Thirty HS patients were included; 29 purulent lesions (96.7%) harbored at least one bacterial species. Five (16.7%) swab samples were positive for S. aureus, none of which was positive for PVL genes. Among the 30 purulent disorders included as controls, 8 (26.3%) were positive for S. aureus; of these, 4 strains (50%) expressed LPV. The study results seem to exclude the pathogenetic involvement of S. aureus producing PVL in HS; as a result, PVL does not seem to represent a potential target in the future development of HS treatments.

The Role of the Cutaneous Microbiome in Hidradenitis Suppurativa-Light at the End of the Microbiological Tunnel

The development of next generation sequencing, coupled with advances in bio-informatics, has provided new insights into the role of the cutaneous microbiome in the pathophysiology of a range of inflammatory skin diseases. In fact, it has even been suggested that the identification of specific skin microbial signatures may not only be useful in terms of diagnosis of skin diseases but they may also ultimately help inform personalised treatment strategies. To date, research investigating the role of microbiota in the development of inflammatory skin diseases has largely focused on atopic eczema and psoriasis vulgaris. The role of the microbiome in Hidradenits suppurativa (HS)-also known as acne inversa-a chronic auto-inflammatory skin disease associated with significant morbidity, has received comparatively little attention. This is despite the fact that antimicrobial therapy plays a central role in the treatment of HS. After briefly outlining the clinical features of HS and current treatment strategies, we move on to review the evidence of microbial dysbiosis in HS pathophysiology. We conclude by outlining the potential for metagenomic studies to deepen our understanding of HS biology but more importantly to identify novel and much needed treatment strategies.

Hidradenitis suppurativa: infection, autoimmunity, or both?

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease mainly affecting areas rich in apocrine glands. Clinically, is characterized by painful subcutaneous nodules and if left untreated to pus secretion, abscess and fistula formation. Its frequency is estimated to be 0.5-4% of the general population, affecting women more often. Pathogenesis of HS is still not clearly defined. It seems to be a combination of genetic factors with alterations in the skin microbiome. Furthermore, at tissue (i.e. skin) as well as at serum level, several inflammatory cytokines are upregulated. The most important of the latter are tumor necrosis factor (TNF), interleukin (IL)-1, IL-17, and IL-23. Adding another level of complexity, it has been suggested that keratinocytes might be intrinsically activated, contributing also to the observed inflammation. Interestingly, it has been noted that frequency of HS is increased in some autoimmune rheumatic diseases, such as spondyloarthropathies (SpA). Of note, both HS and SpA have relatively strong association with metabolic diseases and obesity implying that there are indeed some common underlying pathophysiological pathways. Although no specific microbe has been identified, alterations in the microbiome of the skin of these patients have been reported. Of note, microbes with a capability for biofilm formation are abundant. Treatment of HS among others, include antibiotics as well as biologic drugs targeting TNF and other cytokines and used for autoimmune rheumatic diseases. Herein, we review the current evidence on links between HS and autoimmune diseases and infectious diseases with a focus on epidemiology and pathophysiology.

Staphylococcus aureus Carriage Status in Patients with Hidradenitis Suppurativa: An Observational Cohort Study in a Tertiary Referral Hospital in Athens, Greece

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, recurrent, auto-inflammatory disease that affects the pilosebaceous unit in apocrine gland-bearing areas. Bacteria are thought to play a role in the development and progression of disease. In addition, antibiotics are frequently used as first-line management for HS. We sought to determine the carriage status of Staphylococcus aureus and its resistance to antibiotics among patients with HS in a tertiary referral hospital in Athens, Greece.

METHODS

In this observational cohort study, 68 consecutive patients attending the HS clinic of "Attikon" General University Hospital in Athens, Greece, during a 9-month period were enrolled. All patients had not received any antibiotic therapy for any reason during the previous 3 months before enrollment. Nasal and oropharyngeal samplingwere obtained, and specimens were tested for the presence of S. aureus.Antibiotic susceptibility testing was performed using the VITEK 2 system. Standard statistical tests, descriptive statistics tests, and χ2 and Pearson correlation tests were performed, using IBM SPSS Statistics 25.The level of significance was set at a pvalue <0.05.

RESULTS

Sixty-eight patients with HS were studied. There were 44 females (64.7%) and 24 males (35.3%). The mean age was 36.63 ± 13.0 (IQR = 21), and the mean age at onset of disease was 23.90 ± 11.53 (IQR = 14). The mean duration of disease was 12.74 ± 10.20 years (IQR = 15). Fifteen (22.1%) of the patients were Hurley stage I, 22 (32.4%) were Hurley stage II, and 31 (45.6%) were Hurley stage III. S. aureus carriage was detected in 17 patients (25%). Six of them (35.3%) had MRSA strains. There was an increased prevalence of S. aureus colonization (p = 0.058) and MRSA (p = 0.101) in Hurley stage III patients, but this result was not statistically significant.

CONCLUSIONS

We found a 25% prevalence of S. aureus colonization (17/68 patients) and a 35.3% prevalence of MRSA (6/17) among our HS patients. There was an increased prevalence of S. aureusand MRSA positivity in HS patients with Hurley stage III. Further studies are needed to clarify the possible clinical significance of S. aureus carriage in the disease development and progression as well as in the treatment outcome.

Weight Loss and Dietary Interventions for Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa (HS) is a common inflammatory disorder characterized by recurrent, painful, and malodorous abscesses and nodules predominantly in skin folds. HS is associated with substantial morbidity and poor quality of life. There are no curative therapies, and the only approved biologic drug has variable efficacy and requires high doses, making adjunct treatments crucial. An important risk factor for disease severity is obesity. Our primary objective was to conduct a systematic review examining weight loss and dietary interventions, in HS. Our secondary objective was to examine nutritional supplements in HS.A systematic literature search was conducted using Medline, EMBASE, and the Cochrane Database. We included all study types in adults (>18 years), with a minimum sample size of 5, examining the effects of any dietary or weight loss intervention on HS severity. Two authors screened n = 1279 articles of which 9 met inclusion criteria. All included studies were observational and all interventions were associated with various measures of decreased HS severity. Patient-controlled weight loss and bariatric surgery were associated with HS regression, though a subset of patients with significant increase in panniculi experienced exacerbations and required excision of excess skin. Diets demonstrating benefit eliminated dairy and brewer's yeast. Nutritional supplements including zinc gluconate, vitamin D, and riboflavin had a suppressive, rather than curative, effect on HS lesions in single studies. Overall, the reviewed interventions show promise as potential adjunct treatments in a HS management plan. Prospective randomized controlled trials should validate these findings.

A new T helper 17 cytokine in hidradenitis suppurativa: antimicrobial and proinflammatory role of interleukin-26

BACKGROUND

Interleukin (IL)-26 is a signature T helper 17 cytokine described as a proinflammatory and antimicrobial mediator. So far, IL-26 has been reported in several immune-mediated inflammatory diseases, but its involvement in inflammatory skin disorders is poorly known.

OBJECTIVES

To investigate the role of IL-26 in hidradenitis suppurativa (HS), through its involvement in antimicrobial activity.

METHODS

IL-26 was assessed in patients with HS through gene expression and protein analysis at skin and circulating levels. Ex vivo HS organ skin cultures, together with IL-26 antibody treatment, were performed to determine the IL-26 activity. Peripheral blood mononuclear cells (PBMCs) from patients with HS and healthy controls were either silenced or not with IL-26 small interfering (si)RNA in order to measure its antimicrobial, cytotoxic and phagocytic activities against Staphylococcus aureus.

RESULTS

Firstly, we observed that IL-26 is able to modulate the proinflammatory response at the immune cell level. IL-26 was increased in the plasma of patients with HS compared with healthy controls. Subsequently, we explored the bactericidal, cytotoxic and phagocytic activities of PBMCs against S. aureus in patients with HS and healthy controls. These activities were lower in patients with HS than in controls. Remarkably, the killing activities were reduced when healthy control PBMCs were transfected with IL-26 siRNA. However, the transfection did not affect the killing activity of HS PBMCs, supporting the idea that IL-26 lacks efficacy in HS.

CONCLUSIONS

Our findings suggest that infection susceptibility in HS might be related to IL-26. Although the role of bacteria remains controversial in HS, this paper supports that there is a defect of antimicrobial response in these patients. What's already known about this topic? Interleukin (IL)-26 is a T helper 17 cytokine described as an antimicrobial and proinflammatory mediator. IL-26 has been reported in immune-mediated inflammatory diseases, but its involvement in inflammatory skin disorders remains unclear. Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder characterized by deficiency of IL-20 and IL-22 (a close homologue of IL-26), which causes antimicrobial peptide pauperization leading to severe and recurrent skin infections. What does this study add? IL-26 plasma levels are higher in patients with HS than in healthy control individuals. The antimicrobial activity of IL-26 might be ineffective in patients with HS. What is the translational message? Cutaneous antimicrobial incompetence in HS could be related to IL-26.

The skin transcriptome in hidradenitis suppurativa uncovers an antimicrobial and sweat gland gene signature which has distinct overlap with wounded skin

Hidradenitis suppurativa (HS) is a debilitating chronic inflammatory skin disease resulting in non-healing wounds affecting body areas of high hair follicle and sweat gland density. The pathogenesis of HS is not well understood but appears to involve dysbiosis-driven aberrant activation of the innate immune system leading to excessive inflammation. Marked dysregulation of antimicrobial peptides and proteins (AMPs) in HS is observed, which may contribute to this sustained inflammation. Here, we analyzed HS skin transcriptomes from previously published studies and integrated these findings through a comparative analysis with a published wound healing data set and with immunofluorescence and qPCR analysis from new HS patient samples. Among the top differently expressed genes between lesional and non-lesional HS skin were members of the S100 family as well as dermcidin, the latter known as a sweat gland-associated AMP and one of the most downregulated genes in HS lesions. Interestingly, many genes associated with sweat gland function, such as secretoglobins and aquaporin 5, were decreased in HS lesional skin and we discovered that these genes demonstrated opposite expression profiles in healing skin. Conversely, HS lesional and wounded skin shared a common gene signature including genes encoding for S100 proteins, defensins, and genes encoding antiviral proteins. Overall, our results suggest that the pathogenesis of HS may be driven by changes in AMP expression and altered sweat gland function, and may share a similar pathology with chronic wounds.

Inter- and intrarater reliability of Hurley staging for hidradenitis suppurativa

Background

Hidradenitis suppurativa (HS) is a chronic, inflammatory and recurrent skin disease. Different staging instruments have been suggested, but none has achieved universal acceptance. Despite the fact that Hurley staging is one of the most widely applied HS disease severity staging instruments, it has not been validated.

Objectives

To determine the inter‐ and intrarater reliability of the Hurley staging system.

Methods

Fifteen raters (five plastic surgeons, five general surgeons and five dermatologists) independently staged 30 photos of patients with HS according to Hurley staging at two time points. Reliability was assessed using kappa (&kgr;) statistics, and multivariable logistic regressions were used to determine independent risk factors for photos with discordant staging.

Results

Inter‐rater reliability was moderate for the three stages of HS [κ = 0·59, 95% confidence interval (CI) 0·48–0·70]. It was moderate for Hurley stage I (κ = 0·45, 95% CI 0·32–0·55) and stage II (κ = 0·51, 95% CI 0·31–0·71) and it was almost perfect for stage III (κ = 0·81, 95% CI 0·62–1·00). The intrarater reliability was substantial for all stages and all raters (κ = 0·65, 95% CI 0·58–0·72). For stage I it was moderate (κ = 0·50, 95% CI 0·38–0·62), for stage II it was substantial (κ = 0·62, 95% CI 0·51–0·73) and for stage III it was almost perfect (κ = 0·82, 95% CI 0·77–0·87). Hurley stages II and III were less likely to result in discordant staging than Hurley stage I (odds ratios 0·47, 95% CI 0·29–0·77 and 0·21, 95% CI 0·12–0·38, respectively). The mean time spent on staging a photo was 14 s.

Conclusions

Hurley staging is reliable for rapid severity assessment of HS, with moderate inter‐rater and substantial intrarater reliability for all stages. It is best for assessing Hurley stage III HS, which is an indication for surgery.

What's already known about this topic?

Hidradenitis suppurativa is a relatively common disease without a universally accepted disease severity staging instrument.

Hurley staging is one of the most widely applied disease severity staging instruments.

What does this study add?

This study is the first to determine the inter‐ and intrarater reliability of Hurley staging.

Hurley staging is reliable for rapid severity assessment of hidradenitis suppurativa. It is best for assessing Hurley stage III disease, which is an indication for surgery.

Linked Comment: https://doi.org/10.1111/bjd.18158.

https://doi.org/10.1111/bjd.18188 available online

https://www.bjdonline.com/article/inter-and-intrarater-reliability-of-the-hurley-staging-for-hidradenitis-suppurativa/

Human Microbiome: Composition and Role in Inflammatory Skin Diseases

This review focuses on recent evidences about human microbiome composition and functions, exploring the potential implication of its impairment in some diffuse and invalidating inflammatory skin diseases, such as atopic dermatitis, psoriasis, hidradenitis suppurativa and acne. We analysed current scientific literature, focusing on the current evidences about gut and skin microbiome composition and the complex dialogue between microbes and the host. Finally, we examined the consequences of this dialogue for health and skin diseases. This review highlights how human microbes interact with different anatomic niches modifying the state of immune activation, skin barrier status, microbe-host and microbe-microbe interactions. It also shows as most of the factors affecting gut and skin microorganisms' activity have demonstrated to be effective also in modulating chronic inflammatory skin diseases. More and more evidences demonstrate that human microbiome plays a key role in human health and diseases. It is to be expected that these new insights will translate into diagnostic, therapeutic and preventive measures in the context of personalized/precision medicine.

Biofilm production and antibiotic susceptibility of Staphylococcus epidermidis strains from Hidradenitis Suppurativa lesions

BACKGROUND

An aberrant interaction between commensal skin bacteria and the host skin immune system is considered important in the pathogenesis of hidradenitis suppurativa (HS).

OBJECTIVE

In this study, we investigated the antibiotic susceptibility and biofilm-forming capabilities of S. epidermidis strains isolated from HS patients.

METHODS

Skin biopsies were taken from active HS lesions such as inflammatory nodules and/or sinuses and non-involved skin from 26 patients and cultured under optimal microbiological conditions for 24 h. Planktonic growth, biofilm production, antibiotic susceptibility and biofilm eradication by clindamycin, doxycycline, rifampicin and tetracycline were tested including a laboratory control strain of S. epidermidis for reference.

RESULTS

Staphylococcus epidermidis was cultured in 16 of 26 HS patients (62%). In total 27 different S. epidermidis isolates were identified; 16 (59%) from non-involved skin and 11 (41%) from HS lesions. All bacterial strains showed planktonic growth. Twenty-four of 27 (89%) isolates were strong biofilm producers in vitro. The biofilm-forming capability varied amongst the strains from non-involved skin and lesional skin. Twenty-four strains had an intermediate to resistant antibiotic susceptibility to clindamycin (89%). Rifampicin was the most effective antibiotic at inhibiting planktonic growth and at eradication of biofilm (P < 0.05).

CONCLUSION

We observed a slight increase in S. epidermidis virulence, characterized by resistance to commonly used antibiotics, increased biofilm production and resistance to biofilm eradication. In particular, the reduced sensitivity to tetracycline and clindamycin, two standard antibiotics in the treatment of HS, is alarming. Rifampicin, also important in HS treatment, showed the greatest efficacy at eradicating the biofilm at low MIC concentrations.

The Microbiological Landscape of Anaerobic Infections in Hidradenitis Suppurativa: A Prospective Metagenomic Study

Background

Hidradenitis suppurativa (HS) is a frequent and severe disease of the skin, characterized by recurrent or chronic skinfold suppurative lesions with a high impact on quality of life. Although considered inflammatory, antimicrobial treatments can improve or lead to clinical remission of HS, suggesting triggering microbial factors. Indeed, mixed anaerobic microbiota are associated with a majority of HS lesions. Our aim in this study was to characterize the landscape of anaerobic infections in HS using high-throughput sequencing.

Methods

We sampled and cultured 149 lesions and 175 unaffected control skinfold areas from 65 adult HS patients. The microbiome of 80 anaerobic lesions was compared to that of 88 control samples by 454 high-throughput sequencing after construction of 16S ribosomal RNA gene libraries.

Results

Bacterial cultures detected anaerobes in 83% of lesions vs 53% of control samples, combined with milleri group streptococci and actinomycetes in 33% and 26% of cases, respectively. High-throughput sequencing identified 43 taxa associated with HS lesions. Two gram-negative anaerobic rod taxa, Prevotella and Porphyromonas, predominated, contrasting with a reduced abundance of aerobic commensals. These rare taxa of normal skinfold microbiota were associated with lesions independently of gender, duration and familial history of HS, body mass index, and location. Two main additional taxa, Fusobacterium and Parvimonas, correlated with the clinical severity of HS.

Conclusions

In this study we reveal the high prevalence and particular landscape of mixed anaerobic infection in HS, paving the way for rationale targeted antimicrobial treatments.

The Follicular Skin Microbiome in Patients With Hidradenitis Suppurativa and Healthy Controls

Importance

Although the pathogenesis of hidradenitis suppurativa (HS) remains enigmatic, several factors point to potential involvement of the cutaneous microbiome. Insight into the cutaneous microbiome in HS using next-generation sequencing may provide novel data on the microbiological diversity of the skin.

Objective

To investigate the follicular skin microbiome in patients with HS and in healthy controls.

Design, Setting, and Participants

This case-control study obtained punch biopsy specimens from patients with HS (lesional and nonlesional) and healthy controls between October 1, 2014, and August 1, 2016. Data were analyzed from March to November 2016. Patients with HS were recruited from the Department of Dermatology, Zealand University Hospital, Roskilde, Denmark. Biopsy specimens were analyzed at the Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark. None of the participants received any antibiotics (systemic or topical therapy) within 1 month before the study. In patients with HS, biopsy specimens were obtained from lesional skin (axilla or groin) and nonlesional skin. Only nodules containing at least 1 visible hair follicle were biopsied. Biopsy specimens from healthy controls were obtained from the axilla only.

Main Outcomes and Measures

The different microbiomes were investigated using next-generation sequencing targeting 16S and 18S ribosomal RNA.

Results

The skin microbiome was characterized in 30 patients with HS (mean [SD] age, 46.9 [14.0] years; 19 [63% female]) and 24 healthy controls (mean [SD] age, 32.2 [12.0] years; 13 [54% female]). The next-generation sequencing data provided a previously unreported (to our knowledge) characterization of the skin microbiome in HS. The study demonstrated that the microbiome in HS differs significantly from that in healthy controls in lesional and nonlesional skin. Overall, the following 5 microbiome types were identified: Corynebacterium species (type I), Acinetobacter and Moraxella species (type II), Staphylococcus epidermidis (type III), Porphyromonas and Peptoniphilus species (type IV), and Propionibacterium acnes (type V). In lesional skin, microbiome types consisted predominantly of type I or type IV. Microbiome type IV was not detected in healthy controls. Several taxa, including Propionibacterium, showed a significantly higher relative abundance in healthy controls vs HS skin, indicating that Propionibacterium may be part of the pathogenesis in HS.

Conclusions and Relevance

The study findings suggest a link between a dysbiotic cutaneous microbiome and HS.

SAPHO syndrome associated with hidradenitis suppurativa and pyoderma gangrenosum successfully treated with adalimumab and methotrexate: a case report and review of the literature

SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome is a rare inflammatory condition describing the combination of skin, bone, and joint manifestations that has a heterogeneous presentation. We report a case of severe SAPHO syndrome in association with hidradenitis suppurativa and pyoderma gangrenosum in a 27-year-old male. The patient had an initial migratory arthritis affecting the knees, ankles, metacarpophalangeal joints, proximal interphalangeal joints, wrists, shoulder, and lower back, which progressed to a persistent arthritis and swelling at the sternum, shoulders, wrists, hands, feet, and lower back. Radiographic changes were consistent with the diagnosis of SAPHO syndrome. Serum proinflammatory cytokine levels were significantly elevated and improved substantially after 3 months of therapy. Rationale for therapy in this patient was the observation that tumor necrosis alpha antagonists have been successfully used in SAPHO syndrome, and since arthropathy was so prominent in our patient, we elected to use adalimumab combined with methotrexate.

Medical and Surgical Treatment of Hidradenitis Suppurativa: A Review

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

Bacterial biofilm in chronic lesions of hidradenitis suppurativa

BACKGROUND

Chronic nonhealing or recurrent inflammatory lesions, reminiscent of infection but recalcitrant to antibiotic therapy, generally characterize biofilm-driven diseases. Chronic lesions of hidradenitis suppurativa (HS) exhibit several characteristics, which are compatible with well-known biofilm infections.

OBJECTIVES

To determine and quantify the potential presence of bacterial aggregates in chronic HS lesions.

METHODS

In 42 consecutive patients with HS suffering from chronic lesions, biopsies were obtained from lesional as well as from perilesional skin. Samples were investigated using peptide nucleic acid-fluorescence in situ hybridization in combination with confocal laser scanning microscopy. In addition, corresponding histopathological analysis on haematoxylin and eosin slides was performed.

RESULTS

Biofilms were seen in 67% of the samples of chronic lesions and in 75% of the perilesional samples. The mean diameter of aggregates in lesional skin was significantly greater than in perilesional skin (P = 0·01). Large biofilms (aggregates > 50 μm in diameter) were found in 42% of lesional samples and in only 5% of the perilesional samples (P = 0·009). The majority of the large biofilms were situated in sinus tracts (63%) or in the infundibulum (37%). The majority of the sinus tract samples (73%) contained active bacterial cells, which were associated with inflammation.

CONCLUSIONS

This study suggests that biofilm formation is associated with inflammation of chronic HS lesions. The aggregates most likely occur as a secondary event, possibly due to predisposing local anatomical changes such as sinus tracts (tunnels), keratinous detritus and dilated hair follicles.

An Update on Medical Treatment Options for Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by recurrent inflammatory nodules mostly located in the armpits and groin. Over the years multiple treatments for HS have been proposed; however, to date a cure is still lacking. In this update we provide an overview of most drug treatments reported on for HS, where possible with their mode of action and side effects. In mild cases, clindamycin lotion or resorcinol cream have proven effective. Tetracyclines are a first-line systemic option in more widespread or severe cases, followed by the combination of clindamycin and rifampicin. However, the recurrence rate is high after discontinuation of clindamycin plus rifampicin combination therapy. Long-term treatment with retinoids, especially acitretin is feasible, although teratogenicity has to be taken into account in females of reproductive age. Multiple anti-inflammatory drugs have been suggested for HS, such as dapsone, fumarates or cyclosporine. However, their effectiveness in HS is based on small case series with varying results. If most common treatments have failed, biologics (e.g., infliximab or adalimumab) are the next step. Although not addressed in this review, surgical interventions are often needed to achieve remission.

The Microbiology of Hidradenitis Suppurativa

Although the clinical presentation of Hidradenitis Suppurativa (HS) is strongly reminiscent of bacterial infection, the role of bacteria remains controversial. Studies have isolated an array of different bacterial specimens as well as biofilm formation in lesional HS skin. Consistent findings of Gram-positive cocci and -rods including Staphylococus aureus, Coagulase-negative staphylococci (CoNS) and Corynebacterium species (spp) in deep tissue samples have been demonstrated in HS. Although efficacy of antibiotics, i.e., rifampicin, clindamycin or tetracycline may support a microbial role in disease pathogenesis, the most often isolated bacterial specimens are commensal bacteria (CoNS).

Inflammatory Mechanisms in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic relapsing disease of follicular occlusion that causes immense clinical and psychosocial morbidity when refractory to treatment. HS is no longer considered a disease of primary infectious etiology, although bacteria play a role. There is increasing evidence that HS is associated with immune dysregulation, based on its clinical association with other immune-mediated disorders, by its response to biologic therapy in the clinical arena, and from molecular research. This article summarizes what is known in relation to the inflammatory pathways in HS.

Bacterial pathogens associated with hidradenitis suppurativa, France

Hidradenitis suppurativa (HS) is a skin disease characterized by recurrent nodules or abscesses and chronic suppurating lesions. In the absence of clear pathophysiology, HS is considered to be an inflammatory disease and has no satisfactory medical treatment. Recently, prolonged antimicrobial treatments were shown to improve or resolve HS lesions. We prospectively studied the microbiology of 102 HS lesions sampled from 82 patients using prolonged bacterial cultures and bacterial metagenomics on 6 samples. Staphylococcus lugdunensis was cultured as a unique or predominant isolate from 58% of HS nodules and abscesses, and a polymicrobial anaerobic microflora comprising strict anaerobes, milleri group streptococci, and actinomycetes was found in 24% of abscesses or nodules and in 87% of chronic suppurating lesions. These data show that bacteria known to cause soft tissue and skin infections are associated with HS lesions. Whether these pathogens are the cause of the lesions or are secondary infectious agents, these findings support targeted antimicrobial treatment of HS.

Recalcitrant Hidradenitis Suppurativa: An Investigation of Demographics, Surgical Management, Bacterial Isolates, Pharmacologic Intervention, and Patient-reported Health Outcomes

Hidradenitis suppurativa (HS) is characterized by chronic inflammation, recurrent abscesses, and scarring. Surgery is performed when medical management and antibiotic therapy fails. This study sought to evaluate the demographics, surgical procedures, bacteriology, pharmacologic intervention, and quality of life of patients with recalcitrant HS requiring surgical intervention. A retrospective chart review was performed of 76 recalcitrant HS patients at the University of Illinois Medical Center. Patient demographics, bacterial culture, and surgery data were reviewed. Quality of life was assessed using the 36-item short-form health survey. Patients were mostly female (73.7%) and African American (81.6%) with a mean duration of symptoms of 8.6 years before surgery. Patients underwent at least one surgical procedure, most often to the axillae (57.6%) and 73.7 per cent received antibiotics. The most common culture isolates were Corynebacterium species (14.0%), Staphylococcus epidermidis (13.1%), and Staphylococcus aureus (10.4%) with varying resistance patterns. Surveyed patients had depressed 36-item short-form health survey physical functioning and social functioning scores. Recalcitrant HS patients with progressive symptomology over approximately nine years before surgical intervention were more likely to be African American women with axillary HS. Quality of life was diminished. We recommend initial treatment of HS with clindamycin and trimethoprim–sulfamethoxazole in clindamycin refractory cases.