Hidradenitis suppurativa: a disease of follicular epithelium, rather than apocrine glands

Hidradenitis Suppurativa in Down Syndrome: A Case Series

BACKGROUND/OBJECTIVES

Many dermatologic and systemic diseases have been reported in association with hidradenitis suppurativa, but its association with Down syndrome is rarely mentioned in the literature. The objective of the current study was to assess the frequency of hidradenitis suppurativa in patients with Down syndrome who visited our clinic over 4 years.

METHODS

We recorded the presenting complaints and dermatologic problems of patients with Down syndrome who visited our clinic from January 2011 to December 2014. Medical photographs were taken. Patients with hidradenitis suppurativa were assessed according to severity and treated with topical and systemic medications.

RESULTS

Twenty-nine new patients with Down syndrome visited our clinic during this period. Eleven had hidradenitis suppurativa. Disease severity included Hurley stages I and II.

CONCLUSION

The presence of hidradenitis suppurativa in 38% of patients with Down syndrome is far higher than would be expected by chance alone.

The critical role of macrophages in the pathogenesis of hidradenitis suppurativa

INTRODUCTION

Hidradenitis suppurativa (HS) is a painful chronic inflammatory disease with a prevalence between 1 and 4% of general population. The pathogenesis of HS long eluded scientists, but growing evidence suggests that it is a consequence of inflammatory dysregulation.

FINDINGS

Recent studies suggest that dysregulated immune response to skin flora and overexpression of inflammatory cytokines leads to chronic skin inflammation seen in HS. Macrophages are the most numerous inflammatory cells found in HS infiltrates and release numerous pro-inflammatory cytokines such as IL-23, and IL-1β and TNF-α, exacerbating the inflammation and contributing to the pathogenesis of HS. Furthermore, in HS, there is dysregulated function of other immune players closely associated with macrophage function including: matrix metalloproteases (MMP) 2 and 9 overexpression, toll-like receptor upregulation, impaired Notch signalling, NLRP3 inflammasome upregulation, and dysregulated keratinocyte function. Lifestyle factors including obesity and smoking also contribute to macrophage dysfunction and correlate with HS incidence.

CONCLUSIONS

The overexpression of pro-inflammatory cytokines and subsequent efficacy of anti-cytokine biologic therapies highlights the importance of managing macrophage dysfunction. Future therapies should target key molecular drivers of macrophage dysfunction such as TLR2 and NLRP3 overexpression.

An Atypical Localized Form of Hidradenitis Suppurativa of the Jawline and Neck Mimicking Severe Cystic Acne on Presentation

Hidradenitis suppurativa (HS) is a chronic and debilitating suppurative disease primarily affecting the axillae, perineum, and inframammary regions, where apocrine sweat glands are present. However, HS can occur in atypical locations. We present an interesting case of a 40-year-old man who developed chronic painful subcutaneous nodules, deep sinus tracts, and abscesses involving the jawline and the anterior aspect of the neck as the only parts of the body affected and who responded satisfactorily to adalimumab and laser hair removal treatment. This case is relevant because it helps clinicians to remember that HS may be isolated to atypical locations, such as the anterior aspect of the neck and chin. It also supports another possible HS pathogenesis which consists of the occlusion of terminal hair follicles rather than being essentially a disorder of the apocrine glands.

Gene expression of sphingolipid metabolism pathways is altered in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a debilitating skin disease characterized by painful recurrent nodules and abscesses caused by chronic inflammation. Early events in the development of HS are believed to occur in the folliculopilosebaceous unit; however, the signaling pathways behind this mechanism are unknown. Sphingolipids, such as ceramide, are essential components of the skin and appendages and have important structural and signaling roles.

OBJECTIVE

We sought to explore whether the gene expression of enzymes involved in sphingolipid metabolic pathways is altered in HS.

METHODS

A microarray data set including 30 samples was used to compare the expression of sphingolipid-related enzymes in inflammatory skin lesions from HS patients (n = 17) with the expression in clinically healthy skin tissue (n = 13). Differential expression of sphingolipid metabolism-related genes was analyzed using Gene Expression Omnibus 2R.

RESULTS

HS lesional skin samples have significantly decreased expression of enzymes generating ceramide and sphingomyelin, increased expression of enzymes catabolizing ceramide to sphingosine, and increased expression of enzymes converting ceramide to galactosylceramide and gangliosides.

LIMITATIONS

Limitations of this study include assessing the expression of sphingolipid-related enzymes without assessing the levels of the related sphingolipids.

CONCLUSION

Our study suggests that sphingolipid metabolism is altered in HS lesional skin compared with normal skin.

Non-surgical treatments for hidradenitis suppurativa: A systematic review

INTRODUCTION

The management of hidradenitis suppurativa is multidisciplinary, involving general measures, medical treatment and surgery. Non-surgical treatments, often first-line procedures, mainly concern forms of low-to-moderate severity or, conversely, very severe forms in non-operable patients or those refusing surgery. While many treatments have been attempted, few randomized controlled trials have been conducted, so the choice of treatments is most often based on the personal experience of the clinicians. The objective of this systematic review is to propose a synthetic analysis of the currently available non-surgical procedures.

METHODS

This systematic review of the literature was conducted in accordance with the PRISMA criteria. We searched for articles in the Medline^®, PubMed Central, Embase and Cochrane databases published between January 2005 and September 2015.

RESULTS

Sixty-four articles were included. They generally had a low level of evidence; indeed, the majority of them were retrospective observational studies. They involved biotherapy (44%), dynamic phototherapy (16%), antibiotics (11%), Laser (8%), retinoids (6%) and immunosuppressive therapies, anti-inflammatory drugs, zinc, metformin, gammaglobulins and fumarates.

CONCLUSIONS

None of the non-surgical treatments can treat all stages of the disease and offer long-term remission. Antibiotics and biotherapy seem to have real effectiveness but their effect remains suspensive and the disease is almost certain to reappear once they are stopped. As regards antibiotics, no association has shown their superiority in a study with a high level of evidence. And while some biotherapies seem quite effective, due to their side effects they should be reserved for moderate-to-severe, resistant or inoperable forms of the disease. Randomized controlled studies are needed before valid conclusions can be drawn. In the resistant or disabling forms, it is consequently advisable to orientate to the greatest possible extent towards radical surgery, which is the only treatment allowing hope for cure.

Hidradenitis suppurativa: from pathogenesis to diagnosis and treatment

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease primarily affecting apocrine gland-rich areas of the body and presenting with painful nodules, abscesses, sinus tracts, and scarring. HS 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 (perifollicular lympho-histiocytic inflammation), finally leading to the development of clinical HS lesions. HS has a destructive impact on the patient’s quality of life, being a very challenging disease. Available treatments are limited, mostly off-label and with high variability in the reported efficacy. Fortunately, a monoclonal antibody against tumor necrosis factor alpha has been recently approved for treatment of moderate to severe HS, offering patients a promising new option. This review focuses on the main features of HS, including epidemiology, clinical aspects, pathogenesis, severity classifications, comorbidities, and currently available treatments.

Botulinum Toxin Off-Label Use in Dermatology: A Review

BACKGROUND

Botulinum toxin is a neurotoxin produced by the bacterium Clostridium botulinum which causes a flaccid muscle paralysis. It is currently used for aesthetic treatments and in the focal hyperhidrosis. Recently, botulinum toxin has also been used experimentally in many other dermatological conditions with good results.

OBJECTIVE

To review and analyze the possible botulinum toxin off-label applications published.

METHODS

A retrospective review of the published data was conducted.

CONCLUSIONS

this potent drug can lead to several off-label indications of interest for dermatologists. Further clinical trials are still needed to better understand the real efficacy and safety of these applications and to standardize injection and dose protocols.

Hidradenitis suppurativa treated with tetracycline in combination with colchicine: a prospective series of 20 patients

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder of the follicular epithelium.

OBJECTIVES

The objective of the present study was to evaluate the effectiveness of the combination of tetracycline with colchicine in the treatment of HS.

METHODS

Twenty patients (10 women and 10 men) with HS were included in an open, prospective, pilot study. All patients were treated with 100 mg minocycline administered orally once per day in combination with 0.5 mg colchicine administered twice per day for 6 months followed by a maintenance regimen of 0.5 mg colchicine administered orally twice per day for 3 months. Patients were examined at baseline and thereafter every 3 months for a total of 9 months. The efficacy of the treatment was evaluated using a physician's global assessment (PGA) scale, the Hurley scoring system, and the Dermatology Life Quality Index (DLQI).

RESULTS

A significant improvement in clinical manifestation was reflected in scores on the Hurley scoring system and DLQI. According to the PGA, patients achieved substantial improvement or complete remission. Clinically, all patients started to show signs of improvement within the first 3 months of therapy and continued to improve over the next 6 months.

CONCLUSIONS

This study indicates that the combination of the anti-inflammatory actions of colchicine and minocycline is effective in disease control in HS. Colchicine emerged as a safe option for the maintenance of the obtained result.

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.

Prevalence, Risk Factors, and Comorbidities of Hidradenitis Suppurativa

It is challenging to estimate a true prevalence of hidradenitis suppurativa (HS) because it is underdiagnosed and misdiagnosed. Prevalences have been reported from 0.00033% to 4.1%. The incidence seems to be rising. In addition to dermatologic symptoms, HS is associated with metabolic syndrome, and increased cardiovascular risk. The majority of HS patients are smokers. Additional somatic comorbidities complicating HS include autoimmune conditions, follicular syndromes, rheumatologic conditions, and malignancies. HS patients are troubled by psychological comorbidities. When treating HS patients it is imperative not only to treat the skin symptoms, but also address the screening and treatment of possible comorbidities.

Hidradenitis Suppurativa

Background:

Hidradenitis suppurativa is a clinically defined disease that causes considerable morbidity for patients. The results of recent studies, which have increased the understanding of this disease, are reviewed.

Objective:

The epidemiology, risk factors, pathogenesis, and treatment of this disease are summarized to help clinicians with practical patient management.

Conclusion:

Hidradenitis suppurativa remains a clinical challenge to patients and physicians alike. Physicians should be familiar with the impact this disease has on the patient and with the range of treatments available. Use of simple incisions as treatment is strongly discouraged. Additional pathogenic as well as therapeutic studies are necessary.

Intrinsic Defect in Keratinocyte Function Leads to Inflammation in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory, debilitating, follicular disease of the skin. Despite a high prevalence in the general population, the physiopathology of HS remains poorly understood. The use of antibiotics and immunosuppressive agents for therapy suggests a deregulated immune response to microflora. Using cellular and gene expression analyses, we found an increased number of infiltrating CD4(+) T cells secreting IL-17 and IFN-γ in perilesional and lesional skin of patients with HS. By contrast, IL-22-secreting CD4(+) T cells are not enriched in HS lesions contrasting with increased number of those cells in the blood of patients with HS. We showed that keratinocytes isolated from hair follicles of patients with HS secreted significantly more IL-1β, IP-10, and chemokine (C-C motif) ligand 5 (RANTES) either constitutively or on pattern recognition receptor stimulations. In addition, they displayed a distinct pattern of antimicrobial peptide production. These findings point out a functional defect of keratinocytes in HS leading to a balance prone to inflammatory responses. This is likely to favor a permissive environment for bacterial infections and chronic inflammation characterizing clinical outcomes in patients with HS.

Management of Hidradenitis Suppurativa in Patients with Metabolic Comorbidities

Hidradenitis suppurativa is a chronic inflammatory skin condition associated with an increased prevalence of individual metabolic conditions such as insulin resistance, obesity, hyperlipidemia, hypertension, and with the metabolic syndrome, as a constellation of these risk factors. This places affected patients at an increased risk of early cardiovascular morbidity and mortality. Moreover, many of the therapeutic options, including the newer biologics, used in the treatment of hidradenitis suppurativa have both beneficial and adverse metabolic effects. Therefore, it is critical for physicians to consider the complex interactions between the disease process and the treatment options in the holistic management of these patients with an intrinsically higher risk of metabolic consequences. Other chronic systemic inflammatory diseases such as psoriasis and rheumatoid arthritis have been studied more extensively with regard to their associations and share an underlying link with the metabolic syndrome; we can draw upon the existing knowledge in our understanding and management of hidradenitis suppurativa.

Pathophysiology of hidradenitis suppurativa: An update

The pathogenesis of hidradenitis suppurativa (HS) or acne inversa is not completely understood. Recent research has led to greater insight into the mechanisms involved in the disease. The primary defect in HS pathophysiology rests with the hair follicle. Follicular occlusion, followed by follicular rupture, and a foreign body-type immune response are necessary conditions for the development of clinical HS. A specific genetic signature and environmental factors, such as cigarette smoking, microbial colonization, and adiposity, all contribute to the HS phenotype. Translational research focused on the inflammatory mechanisms involved in HS is needed to develop novel therapeutic options for this debilitating disease.

Dysregulated cytokine expression in lesional and nonlesional skin in hidradenitis suppurativa

BACKGROUND

There is a dearth of information on the precise pathogenesis of hidradenitis suppurativa (HS), but immune dysregulation is implicated.

OBJECTIVES

To determine the nature of the immune response in HS.

METHODS

Skin biopsies - lesional, perilesional (2 cm away) and uninvolved (10 cm away) - were obtained from patients with HS and healthy controls. The expression of various cytokines was determined by enzyme-linked immunosorbent assay, flow cytometry and real-time polymerase chain reaction.

RESULTS

The expression of the inflammatory cytokines interleukin (IL)-17, IL-1β and tumour necrosis factor-α was enhanced in lesional skin of patients with HS. In addition, IL17A and IL1B mRNA were enhanced in clinically normal perilesional skin. CD4(+) T cells produced IL-17 in HS, while CD11c(+) CD1a(-) CD14(+) cells were sources of IL-1β. Activated caspase-1 was detected in HS skin and was associated with enhanced expression of NLRP3 and IL18. Inhibition of caspase-1 decreased IL-1β and IL-18 production, suggesting that the caspase-1 pathway participates in IL-1β and IL-18 expression in HS. Abnormal cytokine expression was detected in perilesional and uninvolved skin, which may suggest that subclinical inflammation is present in HS skin prior to the formation of an active lesion.

CONCLUSIONS

This study demonstrates that CD4(+) T cells produce IL-17 in HS and that the IL-17 pathway may be important in HS pathogenesis. CD11c(+) CD1a(-) CD14(+) cells are a source of IL-1β in HS, the production of which was shown to be mediated, in part, via a caspase-1-dependent pathway. These results suggest that IL-17 and the caspase-1-associated cytokines IL-1β and IL-18 may play a role in the pathogenesis of HS.

Lasers and Intense Pulsed Light Hidradenitis Suppurativa

Lasers and intense pulsed light (IPL) treatment are useful for the treatment of hidradenitis suppurativa (HS). Carbon dioxide lasers are used for cutting or vaporization of the affected area. It is a effective therapy for the management of severe and recalcitrant HS with persistent sinus tract and scarring, and can be performed under local anesthesia. HS has a follicular pathogenesis. Lasers and IPL targeting the hair have been found useful in treating HS by reducing the numbers of hairs in areas with HS. The methods have few side effects, but the studies are preliminary and need to be repeated.

Hidradenitis Suppurativa and Wound Management

Hidradenitis suppurativa (HS) is a chronic, burdensome, debilitating disease of the hair follicle. It presents with recurrent painful inflamed and noninflamed lesions usually in specific body areas such as axillary, inguinal, perineal, and genital areas. It is associated with a large range of other diseases and conditions, such as obesity, arthropathy, inflammatory bowel diseases, and sqaumous cell carcinoma. Medical therapy may be systemic or topical, mainly based on antibiotics, retinoids, hormones and immunosuppressive drugs, including biological therapies. Surgical and laser therapies may be a valid therapeutic approach in order to treat locally recurring lesions. The aim of this article is to review the wound healing options after skin excision and laser treatments, with a focus on lesions left to heal by secondary intention, analyzing the efficacy of moist wound dressings, negative pressure wound therapy, bioactive dressings, such as platelet-rich plasma gel and hylarunoic acid scaffold, or autologous keratinocyte suspension in platelet concentrate and skin-grafting tecniques.

Current concepts in the management of hidradenitis suppurativa in children

PURPOSE OF REVIEW

This review is intended to provide the background aetiopathogenetic framework upon which management of this disorder can be based, particularly with relation to new concepts of the pathogenesis of the disorder. The emphasis is on the prevention of the disorder's full expression by addressing the metabolic changes that drive the underlying structural damage and the immune system's subsequent reaction to this damage.

RECENT FINDINGS

The mechanism by which dietary factors impact on this disease are elucidated, the anatomic defect suspected to be responsible for the disorder is introduced, and an updated flow sheet describing and linking the clinicopathological changes recently described are provided.

SUMMARY

Recent work in the understanding of the induction and evolution of the lesions provides a background upon which the preventive regimen and both the medical and surgical approaches can be effectively based.

Hidradenitis Suppurativa/Acne Inversa: Criteria for Diagnosis, Severity Assessment, Classification and Disease Evaluation

BACKGROUND

Hidradenitis suppurativa/acne inversa (HS) is a chronic, inflammatory, recurrent, debilitating disease, which inflicts a significant burden on patients and is associated with comorbid disorders, such as significantly reduced quality of life, depression, stigmatization, inactivity, working disability, impairment of sexual health and several cardiovascular risk factors.

AIMS/METHODS

To implement an expert consensus on the diagnostic criteria, severity and classification assessment, and an assessment of anti-inflammatory treatment effectiveness based on current evidence.

RESULTS

This article provides criteria for diagnosis, severity assessment, classification and evaluation of HS patients.

CONCLUSION

The provided criteria can be used as tools for the promotion of uniformity in HS evaluation and facilitation of early and timely identification and referral in the primary care setting and thorough and efficient evaluation in daily clinical practice.

Aerobic and Anaerobic Bacteriology of Hidradenitis Suppurativa: A Study of 22 Cases

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease of unclear etiology. The role of bacteria in the pathogenesis of disease remains controversial.

MATERIALS AND METHODS

Specimens were obtained from 22 HS patients by direct percutaneous needle aspiration. The collected material was cultured in aerobic and anaerobic conditions, and sensitivity tests were performed.

RESULTS

Of the 22 patients, 32% were culture negative and 68% were culture positive. A total of 16 isolates was obtained, 14 aerobic and 2 anaerobic. Aerobic bacteria were present in 86% of the specimens, whereas only anaerobic bacteria were isolated in 7%. The predominant aerobic species were Proteus mirabilis, Staphylococcus haemolyticus and Staphylococcus lugdunensis. The isolated anaerobic bacteria were Dermacoccus nishinomiyaensis and Propionibacterium granulosum.

CONCLUSION

A variety of aerobic and anaerobic bacteria was isolated from the HS lesions of our patients. In contrast to previous studies, fewer patients were found to be culture positive, and Staphylococcus aureus was isolated in only 1 of them. More studies are necessary to elucidate the controversial role of bacteria in the pathogenesis of HS.

The medical and laser management of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, debilitating skin disease characterized by painful recurrent nodules and abscesses. In advanced stages, sinus tracts form, with resulting fibrotic and cribriform scar formation, leading to dermal contractures and induration of the affected skin. The epidemiology of HS is poorly described, and few population-based studies exist. The reported incidence varies from 0.0003 to 4%. Effective treatment options for HS are limited, and randomized controlled trials addressing the safety and/or efficacy of available treatments are scarce. No medical treatment to date has been approved by the US FDA specifically for the treatment of HS. While some evidence of disease improvement exists with agents including clindamycin and rifampicin, metformin, fumarates, infliximab, and adalimumab, no single treatment has shown overwhelmingly positive outcomes. The lack of randomized controlled trials for most treatments and often disappointing treatment outcomes is disheartening. This study reviews the published evidence for treatment options for HS.

European S1 guideline for the treatment of hidradenitis suppurativa/acne inversa

Hidradenitis suppurativa/acne inversa (HS) is a chronic, inflammatory, recurrent, debilitating skin disease of the hair follicle that usually presents after puberty with painful, deep-seated, inflamed lesions in the apocrine gland-bearing areas of the body, most commonly the axillae, inguinal and anogenital regions. A mean disease incidence of 6.0 per 100,000 person-years and an average prevalence of 1% has been reported in Europe. HS has the highest impact on patients' quality of life among all assessed dermatological diseases. HS is associated with a variety of concomitant and secondary diseases, such as obesity, metabolic syndrome, inflammatory bowel disease, e.g. Crohn's disease, spondyloarthropathy, follicular occlusion syndrome and other hyperergic diseases. The central pathogenic event in HS is believed to be the occlusion of the upper part of the hair follicle leading to a perifollicular lympho-histiocytic inflammation. A highly significant association between the prevalence of HS and current smoking (Odds ratio 12.55) and overweight (Odds ratio 1.1 for each body mass index unit) has been documented. The European S1 HS guideline suggests that the disease should be treated based on its individual subjective impact and objective severity. Locally recurring lesions can be treated by classical surgery or LASER techniques, whereas medical treatment either as monotherapy or in combination with radical surgery is more appropriate for widely spread lesions. Medical therapy may include antibiotics (clindamycin plus rifampicine, tetracyclines), acitretin and biologics (adalimumab, infliximab). A Hurley severity grade-relevant treatment of HS is recommended by the expert group following a treatment algorithm. Adjuvant measurements, such as pain management, treatment of superinfections, weight loss and tobacco abstinence have to be considered.

Update on hidradenitis suppurativa: connecting the tracts

Hidradenitis suppurativa (HS) is a debilitating skin disease characterized by recurrent abscesses, sinus tract formation, and scarring. Prevalence estimates range from 0.053% to 4.1%, although HS is likely an underdiagnosed disease. Although the first reports of HS date back to the mid-19th century, the disease continues to plague patients and physicians desperate for a definitive treatment. Advances in the understanding of the disease process include the possibility of a defective basement membrane at the sebofollicular junction of the folliculopilosebaceous unit (FPSU; that is, where the sebaceous gland empties into the hair follicle) as an initiating event followed by secondary bacterial colonization. New evidence suggests that bacteria living in a community, known as a biofilm, rather than single planktonic bacteria in HS lesions may explain why HS can be resistant to current antibiotic treatment regimens. Available treatment options have expanded to include triple-antibiotic therapy, tumor necrosis factor (TNF-α) and interleukin-1 (IL-1) inhibitors (biologics), laser therapy, and surgical excision, including the skin tissue-sparing excision with electrosurgical peeling procedure. Despite the array of treatments available, many patients continue to struggle with the embarrassment, pain, odor, and frustration that accompany this often isolating disease. Physicians should address comorbidities in HS, including the psychosocial issues patients with HS frequently encounter. Patients can be directed to HS support groups, where they can openly discuss their frustrations, share their experiences in dealing with HS, and band together to advocate for themselves. HS is misunderstood by both patients and physicians, often resulting in a delay in clinical presentation and diagnosis. Patients and physicians across multiple specialties must work together to expand awareness of and interest in HS, so that one day, individuals with HS can be freed from this crippling disease.

Hidradenitis suppurativa

Hidradenitis suppurativa is a chronic relapsing disorder of the folliculopilosebaceous units (FPSUs). Its negative impact on quality of life is extreme, mainly due to the lack of early recognition, accurate diagnosis, and appropriate management. The support structure of the FPSUs is defective. Under the influence of endogenous reproductive hormones, exogenous hormones, androgens and their precursors in dairy products, and other dietary factors, the follicular unit is plugged and distended by retained keratin. Friction, shearing forces, and pressure lead to rupture and leakage of the ductal contents from the weakened FPSU, causing an inflammatory reaction mediated mainly by the innate immune system. Therapy requires patient comprehension and cooperation, counseling, aggressive hormonal and dietary modification, avoidance of the trauma that leads to rupture, active multimodal anti-inflammatory therapy, and early unroofing and debridement. The full therapeutic program is needed to avoid the aggressive surgery required if the condition is not diagnosed early and managed appropriately.

Hidradenitis suppurativa: the role of immune dysregulation

Hidradenitis suppurativa (HS) is a chronic relapsing inflammatory disease of follicular occlusion characterized by boils, sinus tracts, fistulae, and scarring. It has a significant underestimated morbidity. Antimicrobial, immunosuppressive, anti-androgenic, and surgical approaches have been used with varying results. Knowledge of the pathogenesis of HS is fragmented, and treatment choices have hitherto been empiric without an exact understanding of the scientific basis for their use. Tumor necrosis factor-α inhibitors have shown promise in the treatment of HS in recent years, and the concept of HS as an immunological condition has come to the fore. The focus of this review is to discuss the immunological abnormalities underpinning HS as elucidated to date.

Hidradenitis suppurativa: MRI features in anogenital disease

BACKGROUND

Hidradenitis suppurativa is a rare chronic inflammatory disorder of apocrine gland-bearing skin, which commonly affects the anogenital region. There has been very little literature to date on the MRI appearances of anogenital hidradenitis suppurativa.

OBJECTIVE

The aim of this study was to assess the MRI features of anogenital hidradenitis suppurativa in the largest cohort of patients to be published to date.

DESIGN

After an institutional review board waiver, patients with hidradenitis suppurativa who were undergoing MRI for anogenital disease between 2005 and 2012 were identified from our institutional database. The MRI appearances were recorded by 2 radiologists in consensus, blinded to clinical details. Location of disease, number of tracts, presence of anal fistula, and supralevator involvement were recorded. Patient demographics were also noted.

SETTINGS

This study was conducted at the Department of Radiology, Guy's and St Thomas' National Health Service Foundation Trust.

PATIENTS

Patients included were those undergoing MRI for anogenital disease in hidradenitis suppurativa between 2005 and 2012.

MAIN OUTCOME MEASURES

The distribution of sinus tracts in anogenital hidradenitis suppurativa on MRI was measured.

RESULTS

Thirty-one MRIs were performed in 18 patients (15 men; mean age, 46 years). On the baseline MRI, multiple tracts were seen in the natal cleft (16/18; 83%), the perianal (12/18; 61%), the perineal (13/18; 56%), and the gluteal (8/18; 44%) regions. A communication with the anal canal was present in only 4 patients. Three patients had supralevator extension. Seven patients had follow-up MRIs with variable response to interval treatment: 3 of 7 showed responding disease, 3 of 7 showed stable disease, and 1 of 7 showed progressive disease.

LIMITATIONS

This study was limited by its relatively small cohort of patients.

CONCLUSIONS

In hidradenitis suppurativa, anogenital disease is usually subcutaneous but extensive, with only a minority of patients demonstrating deeper involvement. MRI may help define the extent of anogenital disease and assess response to treatment.

Microbiology of hidradenitis suppurativa (acne inversa): a histological study of 27 patients

Hidradenitis suppurativa (acne inverse) (HS) is a chronic skin disease primarily affecting hair follicles. The aetiology of HS is unknown, but infection is believed to play some role. This retrospective study investigated the microbial colonization directly in skin appendices in HS skin samples. Archival samples from 27 patients with HS were screened by immunofluorescence labelling with monoclonal and polyclonal antibodies against Gram-positive bacteria, Propionibacterium acnes and Propionibacterium granulosum. Fluorescence in situ hybridization was used for further species identification of Staphylococcus spp. Overall, 17 patients (63%) were found positive for bacterial colonization. Of these, 15 showed colonization in hair follicles and/or sinus tracts. The most commonly identified bacteria were DAPI labelled coccoids that were seen in 71% of the positive patients in the form of biofilms and microcolonies. P. acnes was found as biofilms in hair follicles of two patients. Staphylococcus aureus and coagulase-negative staphylococci were not detected in any sample. The results of this study indicate a common bacterial presence in HS skin lesions. Bacterial biofilms are not uncommon and their pathogenic role needs further evaluation.

Preliminary findings suggest hidradenitis suppurativa may be due to defective follicular support

BACKGROUND

The initial pathology in hidradenitis suppurativa (HS)/acne inversa takes place in the folliculopilosebaceous unit (FPSU) and its surrounding tissue. The process involves follicular hyperkeratosis, inflammation and perifolliculitis. Identification of the exact origin of inflammation may shed new light on the pathogenesis and aetiology of the disease.

OBJECTIVES

To study the morphology of the basement membrane zone (BMZ) in patients with HS.

METHODS

In total, 65 operative specimens from 20 patients diagnosed with HS were cut stepwise. Within each specimen, the focus was set on heavily involved HS regions (centre) and clinically uninvolved regions (border). All specimens were stained with periodic acid-Schiff (PAS) to visualize the epithelial support structures of the FPSU (i.e. the BMZ), the sinus tracts (STs) and the interfollicular basement membrane (BM). The intensity of BMZ PAS staining was graded from 0 to 4+.

RESULTS

Compared with the axillary skin of human controls, the sebofollicular junction in patients with HS was found to be almost devoid of PAS-positive material (grade 0/1+) in both the border and centre lesions of HS, whereas STs and BMs showed uniformly grade 2-3+ positivity irrespective of any inflammation present. The distribution of inflammatory cells around the sebofollicular junction occurred predominantly in areas of BMZ thinning.

CONCLUSIONS

The BMZ PAS positivity of clinically uninvolved FPSUs of patients with HS appears to be wispy or not present at all. It is speculated that this may explain the apparent fragility of the sebofollicular junction. There is an increased concentration of inflammatory cells adjacent to these areas, while inflammatory cells are scarce in areas where the PAS-positive material is intact. It is hypothesized that the PAS gap identifies (i) areas susceptible to leakage, trauma and rupture, leading to release of materials that trigger inflammatory mediators, and (ii) the seeding of the dermis with free-living stem cells generating benign but invasive epithelialized sinuses, spreading horizontally in and below the dermis.

Impaired Notch-MKP-1 signalling in hidradenitis suppurativa: an approach to pathogenesis by evidence from translational biology

Recent findings in familial hidradenitis suppurativa (HS) demonstrated loss-of-function mutations of components of the γ-secretase (GS) complex leading to decreased protease cleaving activity, which may compromise canonical Notch signalling. Appropriate Notch signalling is of pivotal importance for maintaining the inner and outer root sheath of the hair follicle and skin appendages. This viewpoint on the pathogenesis of HS is primarily supported by circumstantial evidence derived from translational biology. Impaired Notch signalling is proposed to be the major pathogenic mechanism of HS. Deficient Notch signalling switches the fate of outer root sheath cells, resulting in conversion of hair follicles to keratin-enriched epidermal cysts. Impaired Notch signalling may compromise apocrine gland homoeostasis as well. Damage-associated molecular pattern molecules released by either ruptured epidermal cysts exposing keratin fibres or altered structural components of less maintained apocrine glands may both stimulate TLR-mediated innate immunity. All aggravating factors of HS, that is, smoking, obesity, skin occlusion, androgens and progesterone, may further promote inflammation by release of proinflammatory cytokines derived from activated monocyte/macrophages. Inappropriate Notch signalling may not only initiate inflammation in HS but may lead to insufficient feedback inhibition of overstimulated innate immunity. Regular Notch signalling via induction of MAPK phosphatase-1 (MKP-1) terminates TLR-MAPK-signalling in macrophages and IL-23 secreting DCs, the key players for Th17 cell polarization. Thus, impaired Notch signalling links HS to other Th17-driven comorbidities. All major therapeutic interventions in HS appear to attenuate increased MAPK activation of innate immune cells due to impaired Notch-mediated feedback regulation of innate immunity.

Acne inversa goes an extra mile than hidradenitis suppurativa

Acne inversa (AI, hidradenitis suppurativa, Velpeau’s disease, Verneuil’s disease) is a severe, chronic inflammatory dermatosis of unknown etiology, detected on the basis of clinical symptoms more frequently in women than in men. Purulent lesions in the form of nodules and inflammatory tumors, fistulas and scars are present in the areas with hair follicles and apocrine glands, most commonly on the armpits, groin, around the anus and pubic region. Acne inversa can lead to physical and mental disorders. Unfortunately, it is often misdiagnosed and ineffectively treated. The paper presents a case of a 46-year-old patient who was successfully treated surgically for AI around the anus and buttocks by excision of the changes and closure of the wound with local flaps and split-thickness skin grafts, taken with dermatome from the rear surface of the thighs. Surgical treatment is the method of choice in the treatment of severe AI.

Hidradenitis suppurativa: viewpoint on clinical phenotyping, pathogenesis and novel treatments

Hidradenitis suppurativa (HS) is an inflammatory, debilitating follicular skin disease with recurring flare-ups. The painful, deep-seated, inflamed lesions in the inverse areas of the body cause severe discomfort, and hence, serious psycho-social and economic costs. HS is common, but often misdiagnosed and mechanistically poorly understood. Furthermore, HS is notoriously difficult to treat resulting in a high unmet medical need. To provoke debate, rational experimentation and initiate strategic studies, we here present a concise viewpoint on seven topics: the diagnosis of HS, the role of mechanical friction, the critical importance of accurate clinical subgrouping, smoking and obesity, the role of bacteria, and our comprehensive view on HS pathogenesis with a central role for keratin clearance, and novel treatment approaches.

Pharmacologic interventions for hidradenitis suppurativa: what does the evidence say?

BACKGROUND

Hidradenitis suppurativa is a chronic debilitating skin disease that is recalcitrant to treatment.

OBJECTIVE

The aim of this article was to conduct an evidence-based review of pharmacologic interventions for the treatment of hidradenitis suppurativa (HS).

METHODS

A systematic search of MEDLINE, EMBASE, and the Cochrane database was conducted to identify controlled trials (randomized controlled trials, cohorts, and case-control studies) published in English. The abstracts were examined using predetermined inclusion and exclusion criteria. The identified studies were used to develop the recommendations. Clinically relevant outcomes that were assessed were: clinical remission, patient global assessment, physician global assessment, number of skin lesions, and improvement in Hurley's stage, or Sartorius score.

RESULTS

Overall there was sparse evidence to support the use of any treatment modality. There is fair evidence to support the use of antibacterials in HS and they should be used as first-line therapy (level II-1/grade B). There is fair evidence to support the use of intravenous infliximab in the treatment of advanced HS (Hurley's stage II and III). Given the high cost of anti-tumor necrosis factor therapy and its adverse-effect profile, intravenous infliximab should be offered to patients with severe disease affecting their daily activities who have failed antibacterial therapy (level I/grade B). There is insufficient evidence to support the use of antiandrogens in HS; consideration could be given to their use in women with mild to moderate disease (Hurley's stage I and II) who have failed antibacterial therapy and women with an abnormal hormone profile (level II-2/grade I).

CONCLUSIONS

The existing evidence suggests that antibacterials and anti-tumor necrosis factor therapy are effective in the treatment of HS. Further research is required to confirm the efficacy of the different medications within these groups and to explore the efficacy of other treatment modalities.

Metformin for the treatment of hidradenitis suppurativa: a little help along the way

BACKGROUND

Despite recent insights into its aetiology, hidradenitis suppurativa (HS) remains an intractable and debilitating condition for its sufferers, affecting an estimated 2% of the population. It is characterized by chronic, relapsing abscesses, with accompanying fistula formation within the apocrine glandbearing skin, such as the axillae, ano-genital areas and breasts. Standard treatments remain ineffectual and the disease often runs a chronic relapsing course associated with significant psychosocial trauma for its sufferers.

OBJECTIVE

To evaluate the clinical efficacy of Metformin in treating cases of HS which have not responded to standard therapies.

METHODS

Twenty-five patients were treated with Metformin over a period of 24 weeks. Clinical severity of the disease was assessed at time 0, then after 12 weeks and finally after 24 weeks. Results were evaluated using Sartorius and DLQI scores.

RESULTS

Eighteen patients clinically improved with a significant average reduction in their Sartorius score of 12.7 and number of monthly work days lost reduced from 1.5 to 0.4. Dermatology life quality index (DLQI) also showed a significant improvement in 16 cases, with a drop in DLQI score of 7.6.

CONCLUSION

Metformin helps control HS with minimal side effects and good patient compliance and can represent a further agent in the spectrum of treatments available in the treatment of this disease.

Management of regional hidradenitis suppurativa with vacuum-assisted closure and split thickness skin grafts

BACKGROUND

Hidradenitis suppurativa can be a debilitating chronic illness. The underlying cause of the disease is still not clear, but effective treatment of widespread regional disease relies on resection of all the involved skin and subcutaneous tissue. Closure of the resulting large wound is dependent on either flap or skin graft coverage. Many of the resulting wounds are too large for flap closure or result in unacceptable flap donor site deficits.

METHODS

We present a series of 11 patients with 24 regional disease sites treated with a protocol of excision, followed by wound vacuum-assisted closure (VAC; KCI, San Antonio, TX) therapy to stimulate angiogenesis of exposed fat, and then skin grafting with the use of VAC to support the grafts on the recipient sites.

RESULTS

Only 3 of the patients required regrafting. One patient had a VAC failure because of poor patient compliance, and 1 patient had 4 sites that each required regrafting as the epithelium would not fill in the residual open areas as it usually did in other patients. All patients were cured of their local disease.

CONCLUSIONS

Massive regional hidradenitis suppurativa can be successfully managed with wide excision, VAC therapy, and skin grafting to allow these patients to live normal and productive lives.