Familial hidradenitis suppurativa: evidence in favour of single gene transmission

Epidemiology of hidradenitis suppurativa

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

Inborn Errors of Immunity in Hidradenitis Suppurativa Pathogenesis and Disease Burden

Hidradenitis suppurativa (HS), also known as Verneuil's disease and acne inversa, is a prevalent, debilitating, and understudied inflammatory skin disease. It is marked by repeated bouts of pathological inflammation causing pain, hyperplasia, aberrant healing, and fibrosis. HS is difficult to manage and has many unmet medical needs. There is clinical and pharmacological evidence for extensive etiological heterogeneity with HS, suggesting that this clinical diagnosis is capturing a spectrum of disease entities. Human genetic studies provide robust insight into disease pathogenesis. They also can be used to resolve etiological heterogeneity and to identify drug targets. However, HS has not been extensively investigated with well-powered genetic studies. Here, we review what is known about its genetic architecture. We identify overlap in molecular, cellular, and clinical features between HS and inborn errors of immunity (IEI). This evidence indicates that HS may be an underrecognized component of IEI and suggests that undiagnosed IEI are present in HS cohorts. Inborn errors of immunity represent a salient opportunity for rapidly resolving the immunological landscape of HS pathogenesis, for prioritizing drug repurposing studies, and for improving the clinical management of HS.

Hidradenitis Suppurativa: A Perspective on Genetic Factors Involved in the Disease

Hidradenitis Suppurativa (HS) is a chronic inflammatory skin disease of the pilosebaceous unit, clinically consisting of painful nodules, abscesses, and sinus tracts mostly in, but not limited to, intertriginous skin areas. HS can be defined as a complex skin disease with multifactorial etiologies, including—among others—genetic, immunologic, epigenetic, and environmental factors. Based on genetic heterogeneity and complexity, three different forms can be recognized and considered separately as sporadic, familial, and syndromic. To date, several genetic variants associated to disease susceptibility, disease-onset, and/or treatment response have been reported; some of these reside in genes encoding the gamma-secretase subunits whereas others involve autoinflammatory and/or keratinization genes. The aim of this perspective work is to provide an overview of the contribution of several genetic studies encompassing family linkage analyses, target candidate gene studies, and -omic studies in this field. In our viewpoint, we discuss the role of genetics in Hidradenitis suppurativa considering findings based on Sanger sequencing as well as the more recent Next Generation Sequencing (i.e., exome sequencing or RNA Sequencing) with the aim of better understanding the etio-pathogenesis of the disease as well as identifying novel therapeutic strategies.

The Genomic Architecture of Hidradenitis Suppurativa-A Systematic Review

Hidradenitis suppurativa is a chronic, suppurative condition of the pilosebaceous unit manifesting as painful nodules, abscesses, and sinus tracts mostly in, but not limited to, intertriginous skin. Great strides have been made at elucidating the pathophysiology of hidradenitis suppurativa, which appears to be the product of hyperkeratinization and inflammation brought about by environmental factors and a genetic predisposition. The identification of familial hidradenitis suppurativa has sparked research aimed at identifying underlying pathogenic variants in patients who harbor them. The objective of this review is to provide a broad overview of the role of genetics in various aspects of hidradenitis suppurativa, specifically the pathophysiology, diagnosis, and clinical application.

Insights into the Pathogenesis of HS and Therapeutical Approaches

Hidradenitis suppurativa (HS) is a debilitating, chronic, (auto)inflammatory disease primarily affecting apocrine gland-rich areas of the body. Although pathogenic mechanisms responsible for HS have not yet been fully elucidated, it is a multifactorial process whose main target is the terminal follicle. The role of the inflammatory process (and consequently of cytokine milieu) and of several other factors (genetics, lifestyle, hormonal status, microbiome, innate and adaptive immune systems) involved in HS pathogenesis has been investigated (and often defined) over the years with a view to transferring research results from bench to bedside and describing a unique and universally accepted pathogenetic model. This review will update readers on recent advances in our understanding of HS pathogenesis and novel (potential) medical therapies for patients with moderate-to-severe HS.

Hidradenitis suppurativa: A folliculotropic disease of innate immune barrier dysfunction?

The innate immune system of human skin consists of a multi-layered barrier consisting of cells and soluble effector molecules charged with maintaining homeostasis and responding to insults and infections. It has become increasingly clear that these barrier layers become compromised in skin diseases, especially in disorders of an (auto)inflammatory nature. In the case of hidradenitis suppurativa, great strides have been made in recent years in characterizing the underlying breakdown in homeostatic innate immunity, including an increasing understanding of the central role of the hair follicle in this process. This breakdown appears to occur at multiple levels: the pilosebaceous unit, associated epithelium, the cutaneous microbiome, alteration of immune cell function and local molecular events such as complement activation. This review seeks to summarize, contextualize and analyse critically our current understanding of how these innate immune barriers become dysregulated in the early stage(s) of hidradenitis suppurativa, and to speculate on where potential hidradenitis suppurativa research could be most fruitful.

Hidradenitis Suppurativa: Where We Are and Where We Are Going

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

PASH, PAPASH, PsAPASH, and PASS: The autoinflammatory syndromes of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disease usually involving the major skin folds characterized by a multifactorial pathogenesis and a wide spectrum of clinical manifestations. It can also rarely present in association with other diseases as complex clinical syndromes, causing additional diagnostic and therapeutic challenges. Different etiopathologic factors contribute to follicular inflammation and suppurative lesions of syndromic HS, including follicular hyperkeratinization and plugging, as well as activation of autoinflammatory pathways. Patients with syndromic HS frequently have a severe disease course, presenting with atypical skin involvement, signs of systemic inflammation, and resistance to conventional treatments. Systematic classification of syndromic HS is based on clinical, pathogenetic, and genetic factors, but it is constantly evolving due to increased disease awareness. Treatment of syndromic HS is difficult and should be personalized on a case-by-case basis. Investigating syndromic HS can lead to useful insights on genetics and pathogenesis, translating into new clinical approaches for sporadic hidradenitis. We review the classification, clinical presentation, disease associations, and therapeutic management of syndromic HS, focusing mainly on its autoinflammatory syndromes PASH, PAPASH, PsAPASH, and PASS.

Association of Human Leukocyte Antigens Class II Variants with Susceptibility to Hidradenitis Suppurativa in a Caucasian Spanish Population

Hidradenitis suppurativa (HS) is a chronic inflammatory cutaneous disease of the hair follicle typically presenting recurrent, painful, and inflamed lesions on the inverse areas of the body. Although its pathogenesis remains unknown, the immune system appears to play a potential role. To date, two previous studies have not found any association between the Human Leukocyte Antigen system (HLA) and HS. In this study we analyzed the HLA-A, -B, -C; and DRB1, -DQA1, and –DQB1 allele distribution in 106 HS patients and 262 healthy controls from a Caucasian population in Cantabria (northern Spain). HLA-A*29 and B*50 were significantly more common in HS patients and A*30 and B*37 in controls, but these associations disappeared after statistical correction. DRB1*07, DQA1*02, and DQB1*02 were significantly more common in controls (p 0.026, p 0.0012, and p 0.0005, respectively) and the HLA allele DQB1*03:01 was significantly more common in HS patients (p 0.00007) after the Bonferroni correction. The DRB1*07~DQA1*02~DQB1*02 haplotype was significantly more common in controls (p < 0.0005). This is the first study showing an association between HLA-class II and HS. Our results suggest that HLA-II alleles (DRB1*07, DQA1*02, DQB1*02, and DQB1*03:01) and the DRB1*07~DQA1*02~DQB1*02 haplotype could influence resistance or susceptibility to HS.

A novel nicastrin mutation in a three-generation Dutch family with hidradenitis suppurativa: a search for functional significance

Background

Mutations in the γ‐secretase enzyme subunits have been described in multiple kindreds with familial hidradenitis suppurativa (HS).

Objective

In this study, we report a novel nicastrin (NCSTN) mutation causing HS in a Dutch family. We sought to explore the immunobiological function of NCSTN mutations using data of the Immunological Genome Project.

Methods

Blood samples of three affected and two unaffected family members were collected. Whole‐genome sequencing was performed using genomic DNA isolated from peripheral blood leucocytes. Sanger sequencing was done to confirm the causative NCSTN variant and the familial segregation. The microarray data set of the Immunological Genome Project was used for thorough dissection of the expression and function of wildtype NCSTN in the immune system.

Results

In a family consisting of 23 members, we found an autosomal dominant inheritance pattern of HS and detected a novel splice site mutation (c.1912_1915delCAGT) in the NCSTN gene resulting in a frameshift and subsequent premature stop. All affected individuals had HS lesions on non‐flexural and atypical locations. Wildtype NCSTN appears to be upregulated in myeloid cells like monocytes and macrophages, and in mesenchymal cells such as fibroblastic reticular cells and fibroblasts. In addition, within the 25 highest co‐expressed genes with NCSTN we identified CAPNS1,ARNT and PPARD.

Conclusion

This study reports the identification a novel NCSTN gene splice site mutation which causes familial HS. The associated immunobiological functions of NCSTN and its co‐expressed genes ARNT and PPARD link genetics to the most common environmental and metabolic HS risk factors which are smoking and obesity.

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

BACKGROUND

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

OBJECTIVES

To analyze variations between two consecutive Italian Registries on HS.

METHODS

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

RESULTS

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

CONCLUSIONS

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

An Integrated Approach to Unravel Hidradenitis Suppurativa Etiopathogenesis

Hidradenitis suppurativa/acne inversa (HS) is a chronic inflammatory disease involving hair follicles that presents with painful nodules, abscesses, fistulae, and hypertrophic scars, typically occurring in apocrine gland bearing skin. Establishing a diagnosis of HS may take up to 7 years after disease onset. HS severely impairs the quality of life of patients and its high frequency causes significant costs for health care system. HS patients have an increased risk of developing associated diseases, such as inflammatory bowel diseases and spondyloarthropathies, thereby suggesting a common pathophysiological mechanism. Familial cases, which are around 35% of HS patients, have allowed the identification of susceptibility genes. HS is perceived as a complex disease where environmental factors trigger chronic inflammation in the skin of genetically predisposed individuals. Despite the efforts made to understand HS etiopathogenesis, the exact mechanisms at the basis of the disease need to be still unraveled. In this review, we considered all OMICs studies performed on HS and observed that OMICs contribution in the context of HS appeared as not clear enough and/or rich of useful clinical information. Indeed, most studies focused only on one aspect—genome, transcriptome, or proteome—of the disease, enrolling small numbers of patients. This is quite limiting for the genetic studies, from different geographical areas and looking at a few aspects of HS pathogenesis without any integration of the findings obtained or a comparison among different studies. A strong need for an integrated approach using OMICs tools is required to discover novel actors involved in HS etiopathogenesis. Moreover, we suggest the constitution of consortia to enroll a higher number of patients to be analyzed following common and consensus OMICs strategies. Comparison and integration with the findings present in the OMICs repositories are mandatory. In a theoretic pipeline, the Skin-OMICs profile obtained from each HS patient should be compared and integrated with repositories and literature data by using appropriate InterOMICs approach. The final goal is not only to improve the knowledge of HS etiopathogenesis but also to provide novel tools to the clinicians with the eventual aim of offering a tailored treatment for HS patients.

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.

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.

Pathogenesis and pharmacotherapy of Hidradenitis suppurativa

The focus of this review is to discuss the pathogenesis and the pharmacotherapy of Hidradenitis suppurativa (HS). HS is a distressing chronic skin disorder characterized by abscesses, boils, fistulas and scarring, generally affecting the groins, anogenital area and axillae. It is a common disease with an estimated prevalence of 1%. The etiology is unknown. HS was thought to be a disease of the apocrine sweat glands, but histological findings indicate that HS is a disease arising from the hair follicles. Several pathogenic factors seem important including genetic predisposition, smoking, obesity and an aberrant immune response to commensal flora. The management of HS is tremendously challenging because effective therapies are lacking. Nevertheless, HS has been treated with topical and systemic antibiotics, retinoids and immunosuppressive drugs such as anti-TNF-α biologics with partial success. In this review we will also discuss a potential new therapy for HS with the anti-psoriases agent acitretin.

Comorbidities of hidradenitis suppurativa (acne inversa)

Comorbidities of hidradenitis suppurativa (acne inversa) were reviewed by extracting original and review publications included in MEDLINE, EMBASE and COCHRANE libraries using the terms "hidradenitis," "Verneuil" and "acne inversa." Follicular occlusion disorders, inflammatory bowel diseases, especially Crohn disease, spondylarthropathy, other hyperergic diseases, genetic keratin disorders associated with follicular occlusion and squamous cell carcinoma were the most common hidradenitis suppurativa comorbid diseases. A first classification of these major comorbidities and their possible genetic background reveals a list of chromosome loci and genes, which could be hidradenitis suppurativa candidates. Most of these diseases belong to the group of autoinflammatory disorders, where th17 cell cytokines seem to play a central role.

Hidradenitis suppurativa (or Acne inversa) with autosomal dominant inheritance is not linked to chromosome 1p21.1-1q25.3 region

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterized by swollen, painful, inflamed lesions in the axillae, groin, armpits and other parts of the body that contain apocrine glands. The aetiology of HS is unknown, and earlier reports indicate genetic locus responsible for this phenotype on chromosome 1p21.1-1q25.3, but no causative gene(s) have yet been identified. We studied two large multigeneration pedigrees (UR251 and UR252), in which the condition appeared to segregate as an autosomal dominant trait with 100% penetrance. No skipping of generations was observed in either family. Pedigrees consist of 96 individuals, including 25 affected individuals. Because of squamous cell carcinoma, a few deaths were reported in family UR0251. The locus on chromosome 1p21.1-1p25.3, known from previous studies is associated with HS, was excluded in both families by linkage and haplotype analyses. Further studies are in progress to identify the region that is associated with the phenotype in these families.

Squamous cell carcinoma arising from perineal lesion in a familial case of Hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic dermatologic disorder characterised by multiple vesiculopustular cutaneous lesions in skin. It sometimes express autosomal dominant mode of inheritance. In some patients, it can give rise to squamous cell carcinoma of skin. Unlike the usual marjolin's ulcer which develops in chronic scars, this disease carries a grave prognosis with high recurrence rate and mortality. Here we are reporting the case of a 40-year-old gentle man with hidradenitis suppurativa, who presented with squamous cell carcinoma in the perianal region, and had multiple family members affected with HS. A short history and review of literature are discussed. Squamous cell carcinoma arising from HS is a major therapeutic challenge. This malignancy carries very high rates of recurrence and mortality. Careful surveillance of the lesions of HS, especially occurring in perineal region is very important to diagnose secondary malignancies. Similarly, meticulous surgical excision with careful resection of all sinus tracks and frozen section examination of margins are very important to eradicate the disease.

Successful Treatment of Hidradenitis Suppurativa with Infliximab in a Patient Who Failed to Respond to Etanercept

Background:

Hidradenitis suppurativa (HS) is a devastating chronic scarring disease of the axillae, groins, and submammary tissue occurring predominantly in women, with onset at puberty. Multiple treatments have been attempted, with limited success. The association of HS with Crohn disease, psoriasis (PSO), and pyoderma gangrenosum, as well as the seronegative arthropathies, suggests a common immunopathogenesis and has motivated attempts at treatment with anti-tumor necrosis factor (TNF)-α agents, already demonstrated to be efficacious in major inflammatory diseases.

Objective:

To report on the clinical evolution of a patient with HS and PSO treated with infliximab who had failed to respond to etanercept and to discuss the possible mechanism responsible for the outcome.

Methods:

We describe the medical history, diagnostic tests, and clinical evolution of a 25-year-old woman with HS and psoriasis treated with infliximab.

Results:

The patient demonstrated a rapid and complete response with infliximab for the HS and PSO, sustained for 24 months.

Conclusion:

The success of anti-TNF agents such as infliximab in managing HS offers a new therapeutic option and supports an underlying immunologic basis for the disease. The differential response to HS observed with infliximab and etanercept in this patient could be related to differences in structure, binding specificities, or gene suppression.

Hidradenitis suppurativa

Background

Hidradenitis suppurativa is a chronic, recurrent, suppurative cutaneous disease. Despite its incidence, optimal medical or surgical treatment remains unclear. This review describes the disease, ranging from pathogenesis to treatment and prognosis.

Methods

Articles were sourced from PubMed and Medline, using the MeSH terms ‘hidradenitis suppurativa’ and ‘acne inversa’. Selection of articles was based on peer review, journal, relevance and English language.

Results and conclusion

On the basis of histological findings, the disease is now considered inflammatory and originating from the hair follicle; therefore, the term ‘acne inversa’ is favoured by some experts. The exact aetiology remains obscure but smoking seems to be a major triggering factor. Treatment should be individualized according to the site and extent of the disease. Absolute cessation of smoking is essential in the treatment of hidradenitis. Management with antibiotics or other medications may relieve early symptoms, but radical surgery may be necessary for control and to prevent recurrence.

Surgical treatment of hidradenitis suppurativa: case series and review of the literature

The chronic and relapsing nature of hidradenitis suppurativa leads to physical and psychological damage. The absence of a proven cure further worsens the scenario. Patient 1 was a 28-year-old woman with a 10-year history of abscesses and non healing sinuses with foul-smelling discharge from her axilla, submammary and groin areas. This led to an episode of self-harm due to severe depression. After failed medical therapy, she was referred for surgery with wide excision of the skin and healing by secondary intention. Her wounds were managed by our specialist wound clinic with the use of topical and systemic antibiotics and thus remained free from symptoms. Patient 2 was a 32-year-old woman with a similar history for 15 years. Patient 3 was a 41-year-old man with a 20-year history of discharging sinuses and abscesses. All the patients had endured a long period of medical treatment and subsequently required surgery for a long-term relief of symptoms. This has undoubtedly led to psychological symptoms and a decrease in quality of life.

Hidradenitis suppurativa, Dowling-Degos and multiple epidermal cysts: a new follicular occlusion triad

This case illustrates the rare association between hidradenitis suppurativa (HS) and Dowling-Degos disease (DDD). Furthermore the association of HS, DDD and multiple epidermal cysts has not to our knowledge been described before, but their coexistence in the same patient is likely to reflect the same follicular anomaly. It is possible that a single underlying defect of follicular proliferation may account for the coexistence of these conditions.

Hidradenitis suppurativa: a review

Hidradenitis suppurativa is a recurrent disease involving apocrine-bearing skin with a predilection for intertriginous areas, including genital skin. It has a highly variable clinical course. Mild cases may present as recurrent isolated nodules, while severe instances of the disease with chronic inflammation may lead to scarring, functional impairment, and rarely, squamous cell carcinoma. While genetic factors, patient characteristics, hormones and infection play a role in disease expression, a comprehensive understanding of the pathogenesis remains to be elicited. Additionally, effective treatment is largely unknown. While the mainstay of therapy had been surgery, and topical or systemic antimicrobial agents, other therapeutic modalities such as retinoids, hormonal therapy and immunosuppresive medications may also hold some promise.

Hidradenitis suppurativa: pathogenesis and management

Hidradenitis suppurativa (HS) is a chronic disease manifested by recurrent abscesses, sinus tracts and scarring. It arises most commonly, however, not exclusive from apocrine gland bearing skin. This review article sets out to clarify the importance of early diagnosis, the pathogenesis and aetiology of HS, and evidence for medical and surgical therapies for this debilitating disease.HS is caused primarily by follicular occlusion with secondary involvement of the apocrine glands. The aetiology is still poorly understood. There is a genetic component with probable hormonal influence on gene expression. Shearing forces from obesity and tight clothing contribute to its development. Management should be appropriately tailored for the severity and distribution of HS as well as quality of life of the patient. Medical management with appropriate antibiotics, if initiated early, can be successful in mild to moderate severity HS as well as improving disease control prior to attempted curative surgery in severe HS. Other helpful measures include advice on lifestyle changes, intralesional steroids, systemic retinoids, hormonal manipulation, and a revival of interest in the use of radiotherapy for HS. While there is a place for 'conservative' surgical procedures (including CO(2) laser) in selected cases of mild to moderate HS, radical excision of all apocrine-bearing tissue is the definitive treatment. We advocate close interdisciplinary collaboration as well as a cautionary approach to timing and planning of surgery to minimise recurrence rates.

Hidradenitis suppurativa

Hidradenitis suppurativa is a chronic, debilitating disease of apocrine gland-bearing skin. Its management must be individualized according to the site and extent of the disease. Initial conservative measures with antibiotics, local wound care, and limited incision and drainage can alleviate the acute symptoms, but more radical surgery will likely eventually be necessary in order to control and prevent recurrent disease. Options include unroofing and marsupialization, local excision, or more extensive operative excision with primary or secondary closure, skin grafting, or flap coverage of defects. Wide excision will offer the most definitive therapy, with the trade-off being a higher morbidity. Split-thickness skin grafts in the anal canal may contract and result in anal stenosis and should be avoided. Perianal disease is often best managed with local excision alone, with primary closure for small defects, and either unroofing or healing by secondary intention for larger wounds.

Acne inversa (alias hidradenitis suppurativa)

Acne inversa is a recurrent, suppurative disease manifested by abscesses, fistulas, and scarring. Once considered to be a disease of the apocrine glands, it is actually a defect of follicular epithelium. Thus, the term hidradenitis suppurativa is a misnomer and should be abandoned. In cases of familial acne inversa, the pattern of transmission and number of affected individuals are consistent with autosomal dominant inheritance. Aetiological factors such as hyperandrogenism, obesity, smoking and chemical irritants are not consistently associated with the affection. Bacterial involvement is not a primary event in acne inversa, but is secondary to the disease process. Potential complications include dermal contraction, local or systemic infection due to the spread of microorganisms, systemic amyloidosis, arthropathy, and squamous cell carcinoma. As spontaneous resolution is rare and progressive disability is the rule, early definitive surgical intervention is advisable. The surgical procedure of choice in most cases is wide local excision and healing by secondary intention. Pharmacotherapeutic drugs, including synthetic retinoids and antiandrogens, do not prevent progression of the disease.

Pathogenesis, clinical features and management of hidradenitis suppurativa

Hidradenitis suppurativa is a chronic skin condition involving the apocrine glandular zones. Affected patients may present with acute abscesses, but the condition often progresses to a chronic state with persistent pain, sepsis, sinus tract and fistula formation, purulent discharge and dermal scarring. Treatment of patients with severe disease can be difficult and may require complex surgical intervention. This review encompasses the pathogenesis, clinical manifestations and management options for patients with hidradenitis suppurativa.

A gene for pachyonychia congenita is closely linked to the keratin gene cluster on 17q12-q21

Pachyonychia congenita (PC) is a group of hereditary syndromes which have in common a hypertrophic dystrophy of the distal nail, and are associated with a variety of additional features, notably various dyskeratoses of skin and mucous membranes. The pathology is unknown but the array of clinical features suggests the possibility of a keratin abnormality. In the present report we describe linkage analyses in a large PC pedigree of the Jackson-Lawler type, a subtype which is characterised by multiple epidermal cysts, hair abnormalities, and natal teeth. The disease locus in this family was found to be tightly linked to markers mapping within, or very close to, the keratin type I cluster at 17q12-q21; maximum lod scores for linkage of the disease to a KRT10 polymorphism and to D17S800, a marker known to be very tightly linked to KRT10, were respectively +4.51 and +7.73, both at theta = 0.00. Although always likely, our findings provide strong evidence of a keratin gene anomaly underlying an inherited disorder affecting epidermis, nail, hair, and mucosa. These findings permit testing to see if pachyonychia congenita shows any locus heterogeneity and suggest specific candidate keratin genes for mutation searching studies. In addition, they suggest a role for keratins in the phenomenon of natal dentition.

Pachyonychia congenita complicated by hidradenitis suppurativa: a family study

A family is described in which five of the six members with the Jackson-Lawler type of pachyonychia congenita also had varying degrees of hidradenitis suppurativa. We suggest an association between this type of pachyonychia congenita and hidradenitis suppurativa.

The symptomatology of hidradenitis suppurativa in women

In order to establish the possible role of androgen in the development of hidradenitis suppurativa the symptomatology of the disease was studied in a group of 70 female patients. The results were compared with those obtained from an age-matched control group of healthy women. The incidence of women with signs of androgenization in the two groups did not differ significantly. The only significant differences found were a shorter menstrual cycle and a longer duration of menstrual flow in the women suffering from hidradenitis, and that women with hidradenitis were more likely to have a positive family history of hidradenitis. The prevalence of hidradenitis in the control group was 4%. The results show that hidradenitis is not accompanied by other signs of androgenization. The disease may be due to local changes in the apocrine glands of predisposed individuals.

A family study of hidradenitis suppurativa

A family study of hidradenitis suppurativa was undertaken based on 26 subjects with the disease. The probands were obtained from Hospital Activity Analysis (HAA) records for a three year period (1980 to 1983) and by direct referral from hospital specialists over a six month period (1983 to 1984). Family pedigree information was collected by home visits or hospital interviews and confirmation of the disease in relatives was obtained by examination where possible or by telephone contact and hospital/GP records. A total of 62 affected persons was eventually ascertained, 40 females and 22 males. In 11 families there was evidence in favour of a genetic aetiology with single gene transmission. In another three families there was historical evidence of familial occurrence and in nine families no family history was obtained at the time of enquiry. Problems of ascertainment, including variability of age of onset and psychosocial factors, were noted and could be responsible for false negative family histories or underestimation of affected persons.

Evidence of genetic factors in hidradenitis suppurativa

Twenty-six probands suffering from hidradenitis suppurativa were identified from Hospital Activity Analysis (H.A.A.) records for the period 1980-83 and by direct referral from hospital specialists over a 6-month period in 1983-84. Investigation of their families eventually confirmed a total of 62 affected individuals from 23 families. In II families there was evidence in favour of single gene or Mendelian inheritance; in another three there was familial occurrence; in nine families there was a negative family history at the time of enquiry. The disease appears to be commoner than reports suggest and it is probable that there is an underestimation of affected individuals in our community. Problems of identification including variable age of onset and psycho-social factors were found and may be responsible for false-negative family histories.