Interobserver variability of clinical scores in hidradenitis suppurativa is low

How to Define Mild to Severe Hidradenitis Suppurativa? A Simple New Tool Based on Latent Class Analysis of EPIVER Data Study

Purpose

Hidradenitis suppurativa (HS) is an inflammatory skin disease characterized by recurrent or chronic painful and suppurating lesions in the apocrine gland-bearing regions. The lack of knowledge about HS and its extremely heterogeneous clinical presentation, in terms of both lesion appearance and sites of involvement, frequently delay its diagnosis for several years. Objectives: in this study, using the latent class analysis, it was demonstrated that severity of HS could be evaluated not only with clinical or surgical characteristics but also with gender specificities.

Patients and Methods

Clinical and sociodemographic data of HS patients were retrospectively analysed with the latent class method in order to create a classification tool of disease severity.

Results

From the study of 1428 HS patients (544 men and 884 women), two classification models, depending on gender, were developed. Each classification model was composed of three distinct latent classes clearly identified and defined from mild-to-severe cases of HS. These classification models of HS severity were not distorted by patient ages and were coherent with Hurley stages but were more clinically precise.

Conclusion

In this study, a convenient classification tool, useful for facilitating decision support in routine practice, has been developed. This tool could be used to define clinical subgroups within a study population.

Surgical Treatment in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, progressive inflammatory disorder of follicular occlusion with pubertal onset that presents as painful inflammatory nodules, sinus tracts, and tunnelling in apocrine-gland-rich areas, such as the axilla, groin, lower back, and buttocks. The disease course is complicated by contractures, keloids, and immobility and is often associated with a low quality of life. It is considered a disorder of follicular occlusion with secondary inflammation, though the exact cause is not known. Management can often be unsatisfactory and challenging due to the chronic nature of the disease and its adverse impact on the quality of life. A multidisciplinary approach is key to prompt optimal disease control. The early stages can be managed with medical treatment, but the advanced stages most likely require surgical intervention. Various surgical options are available, depending upon disease severity and patient preference. In this review an evidence-based outline of surgical options for the treatment of HS are discussed. Case reports, case series, cohort studies, case-control studies, and Randomized Clinical Trials (RCT)s available in medical databases regarding surgical options used in the treatment of HS were considered for the review presented in a narrative manner in this article.

Trends in Hidradenitis Suppurativa Disease Severity and Quality of Life Outcome Measures: Scoping Review

BACKGROUND

Although there has been an increase in the number of randomized controlled trials evaluating treatment efficacy for hidradenitis suppurativa (HS), instrument measurements of disease severity and quality of life (QoL) are varied, making the compilation of data and comparisons between studies a challenge for clinicians.

OBJECTIVE

We aimed to perform a systematic literature search to examine the recent trends in the use of disease severity and QoL outcome instruments in randomized controlled trials that have been conducted on patients with HS.

METHODS

A scoping review was conducted in February 2021. The PubMed, Embase, Web of Science, and Cochrane databases were used to identify all articles published from January 1964 to February 2021. In total, 41 articles were included in this systematic review.

RESULTS

The HS Clinical Response (HiSCR) score (18/41, 44%) was the most commonly used instrument for disease severity, followed by the Sartorius and Modified Sartorius scales (combined: 16/41, 39%). The Dermatology Life Quality Index (18/41, 44%) and visual analogue pain scales (12/41, 29%) were the most commonly used QoL outcome instruments in HS research.

CONCLUSIONS

Randomized controlled trials conducted from 2013 onward commonly used the validated HiSCR score, while older studies were more heterogeneous and less likely to use a validated scale. A few (6/18, 33%) QoL measures were validated instruments but were not specific to HS; therefore, they may not be representative of all factors that impact patients with HS.

TRIAL REGISTRATION

National Institute of Health Research PROSPERO CRD42020209582; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020209582.

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.

Could Residents Adequately Assess the Severity of Hidradenitis Suppurativa? Interrater and Intrarater Reliability Assessment of Major Scoring Systems

A wide variety of assessment tools have been proposed for hidradenitis suppurativa (HS) until now, but none of them meets the criteria for an ideal score. Because there is no gold standard scoring system, the choice of the measure instrument depends on the purpose of use and even on the physician’s experience in the subject of HS. The aim of this study was to assess the intrarater and interrater reliability of 6 scoring systems commonly used for grading severity of HS: the Hurley Staging System, the Refined Hurley Staging, the Hidradenitis Suppurativa Severity Score System (IHS4), the Hidradenitis Suppurativa Severity Index (HSSI), the Sartorius Hidradenitis Suppurativa Score and the Hidradenitis Suppurativa Physician’s Global Assessment Scale (HS-PGA). On the scoring day, 9 HS patients underwent a physical examination and disease severity assessment by a group of 16 dermatology residents using all evaluated instruments. Then, intrarater reliability was calculated using intraclass correlation coefficient (ICC), and interrater variability was evaluated using the coefficient of variation (CV). In all 6 scorings the ICCs were >0.75, indicating high intrarater reliability of all presented scales. The study has also demonstrated moderate agreement between raters in most of the evaluated measure instruments. The most reproducible methods, according to CVs, seem to be the Hurley staging, IHS4, and HSSI. None of the 6 evaluated scoring systems showed a significant advantage over the other when comparing ICCs, and all the instruments seem to be very reliable methods. The interrater reliability was usually good, but the most repeatable results between researchers were obtained for the easiest scales, including Hurley scoring, IHS4 and HSSI.

Severity and Area Score for Hidradenitis (SASH): a novel outcome measurement for hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease with a large impact on patients' health-related quality of life. However, reliable and consistent outcome measures to assess body surface area (BSA) of HS have not been established.

OBJECTIVES

To develop and assess the reliability and validity of a novel outcome instrument for assessment of HS BSA in a clinical trial setting.

METHODS

Qualitative interviews and focus groups were conducted from July to August 2015 and October 2017 to January 2018. Evaluation of the measurement was assessed during a single-day grading session with patients in April 2018. Participants, who included clinicians or patients, were recruited from academic medical centres in the U.S. mid-Atlantic region.

RESULTS

Concept elicitation included input from 10 providers, of which 60% (n = 6) were female, 80% (n = 8) dermatology specialists and 20% (n = 2) gynaecology specialists. Cognitive debriefing was conducted with 11 providers, of which 82% (n = 9) were dermatologists and 18% (n = 2) gynaecologists. The evaluation stage included 10 clinicians and 23 patients. The intraclass correlation coefficient (ICC) for inter-rater reliability was 0·60 [95% confidence interval (CI) 0·44-0·74]. The ICC for intrarater reliability was 0·98 (95% CI 0·94-1·00). Transformation of the BSA score resulted in an increase in inter-rater reliability to 0·75 (95% CI 0·62-0·85) or 0·76 (95% CI 0·62-0·85). Scores all demonstrated concurrent validity, with statistically significant correlations with extant scoring methods.

CONCLUSIONS

This novel scale is a reliable and valid HS outcome instrument and may capture a wide range of patients by assessing BSA. Future research is necessary to demonstrate its responsiveness. What's already known about this topic? The major HS disease activity scales rely on lesions counts and have moderate-to-good reliability. Body surface area (BSA) is one of the physical signs included in the Core Outcome Set for HS, but is not a part of existing HS disease activity scales. What does this study add? A novel disease severity scale, the Severity and Area Score for Hidradenitis (SASH), was developed and the psychometric properties assessed. There was high inter-rater reliability of 0·75 and 0·76 when BSA was scored on an ordinal scale, and an excellent intrarater reliability of 0·98. The SASH score also demonstrated convergent validity with extant instruments. What are the clinical implications of this work? The ability of clinicians to accurately assess disease status will be improved. Implementation of the SASH score will help guide and assess the effectiveness of appropriate treatment choice.

A Novel Severity Assessment Scoring System for Hidradenitis Suppurativa

Importance

The variation in both clinical appearance and responses to diverse treatment options emphasize the importance of an accurate, clinically relevant, yet easy-to-use scoring system in hidradenitis suppurativa.

Objective

To propose and provide validation data for the newly designed Severity Assessment of Hidradenitis Suppurativa score.

Design, Setting, and Participants

We prospectively assessed disease severity using Hurley staging and the modified Hidradenitis Suppurativa Score in 355 patients referred to Ruhr-University Bochum Department of Dermatology between March 2016 and June 2017. We also assessed disease severity via the Severity Assessment of Hidradenitis Suppurativa score.

Main Outcomes and Measures

Evaluation and assessment of convergent validity and responsiveness to treatment of the Severity Assessment of Hidradenitis Suppurativa score.

Results

Eighty-eight of the 355 patients (134 [37.7%] men and 221 [62.3%] women with a median [IQR] age of 40 [30-49] years) were classified as Hurley stage I, 221 were Hurley stage II, and 46 were Hurley stage III, with an overall median modified Hidradenitis Suppurativa Score of 31 (interquartile range [IQR], 19.3-53). The median total Severity Assessment of Hidradenitis Suppurativa score was 6 (IQR, 4-9), significantly different among the 3 Hurley groups. The median SAHS score for patients in Hurley stage I was 5 (IQR, 3-6), 6 (IQR, 5-9) for patients in Hurley stage II, and 9 (IQR, 7-12) for patients in Hurley stage III (P < .001, Kruskal-Wallis test). Correlation analysis showed a significant correlation between the modified Hidradenitis Suppurativa Score and the Severity Assessment of Hidradenitis Suppurativa score (r = 0.79, P < .001). Disease severity assessment before and after 3 months of conservative systemic treatment showed a significant correlation between the Severity Assessment of Hidradenitis Suppurativa score and modified Hidradenitis Suppurativa Score. Both the mHSS (P = .001) and the SAHS score (P < .001) significantly differed between the baseline visit (median mHSS, 33 [IQR, 24-52]; median SAHS score, 6 [IQR, 5-9]) and the 3-month visit (median mHSS, 28 [IQR, 15-43.5]; median SAHS score, 5 [IQR, 4-6.3]). The 2 patient-reported items demonstrated excellent test-retest reliability with intraclass correlation coefficient values greater than 0.8.

Conclusions and Relevance

Our validation data demonstrated that the Severity Assessment of Hidradenitis Suppurativa score is a disease severity instrument that significantly correlates with Hurley staging and the modified Hidradenitis Suppurativa Score, and is responsive enough to measure treatment outcome.

Quality of life measurement in hidradenitis suppurativa: position statement of the European Academy of Dermatology and Venereology task forces on Quality of Life and Patient-Oriented Outcomes and Acne, Rosacea and Hidradenitis Suppurativa

This paper is organized jointly by the European Academy of Dermatology and Venereology (EADV) Task Force (TF) on Quality of Life (QoL) and Patient-Oriented Outcomes and the EADV TF on acne, rosacea and hidradenitis suppurativa (ARHS). The purpose of this paper was to present current knowledge about QoL assessment in HS, including data on HS-specific health-related (HR) QoL instruments and HRQoL changes in clinical trials, and to make practical recommendations concerning the assessment of QoL in people with HS. HS results in significant quimp that is higher than in most other chronic skin diseases. HS impact in published studies was assessed predominantly (84% of studies) by the Dermatology Life Quality Index (DLQI). There is a lack of high-quality clinical trials in HS patients where HRQoL instruments have been used as outcome measures. One double-blind randomized placebo-controlled trial on infliximab with low number of participants reported significantly better HRQoL improvement in the treatment group than in the placebo group. Well-designed clinical studies in HS patients to compare different treatment methods, including surgical methods and assessing long-term effects, are needed. Because of lack of sufficient validation, the Task Forces are not at present able to recommend existing HS-specific HRQoL instruments for use in clinical studies. The EADV TFs recommend the dermatology-specific DLQI questionnaire for use in HS patients. The EADV TFs encourage the further development, validation and use of other HS-specific, dermatology-specific and generic instruments but such use should be based on the principles presented in the previous publications of the EADV TF on QoL and Patient-Oriented Outcomes.

Hidradenitis suppurativa/acne inversa: a practical framework for treatment optimization - systematic review and recommendations from the HS ALLIANCE working group

Hidradenitis suppurativa (HS)/acne inversa is a debilitating chronic disease that remains poorly understood and difficult to manage. Clinical practice is variable, and there is a need for international, evidence‐based and easily applicable consensus on HS management. We report here the findings of a systematic literature review, which were subsequently used as a basis for the development of international consensus recommendations for the management of patients with HS. A systematic literature review was performed for each of nine clinical questions in HS (defined by an expert steering committee), covering comorbidity assessment, therapy (medical, surgical and combinations) and response to treatment. Included articles underwent data extraction and were graded according to the Oxford Centre for Evidence‐based Medicine criteria. Evidence‐based recommendations were then drafted, refined and voted upon, using a modified Delphi process. Overall, 5310 articles were screened, 171 articles were analysed, and 65 were used to derive recommendations. These articles included six randomized controlled trials plus cohort studies and case series. The highest level of evidence concerned dosing recommendations for topical clindamycin in mild disease (with systemic tetracyclines for more frequent/widespread lesions) and biologic therapy (especially adalimumab) as second‐line agents (following conventional therapy failure). Good‐quality evidence was available for the hidradenitis suppurativa clinical response (HiSCR) as a dichotomous outcome measure in inflammatory areas under treatment. Lower‐level evidence supported recommendations for topical triclosan and oral zinc in mild‐to‐moderate HS, systemic clindamycin and rifampicin in moderate HS and intravenous ertapenem in selected patients with more severe disease. Intralesional or systemic steroids may also be considered. Local surgical excision is suggested for mild‐to‐moderate HS, with wide excision for more extensive disease. Despite a paucity of good‐quality data on management decisions in HS, this systematic review has enabled the development of robust and easily applicable clinical recommendations for international physicians based on graded evidence.

Prevalence of antinuclear antibodies in hidradenitis suppurativa

AIM

The purpose of this study was to investigate the prevalence of antinuclear antibody (ANA) positivity in a cohort of patients with hidradenitis suppurativa (HS), and to assess the frequency of seroconversion during treatment with tumor necrosis factor (TNF)-α inhibitor therapy.

METHODS

This prospective study was conducted through the Wound Etiology and Healing (WE-HEAL) Study. Immunofluorescence ANA testing was performed at baseline, and repeated when clinically indicated. ANA titers of ≥1 : 160 were considered positive. Data were collected on demographics and disease activity scores including the Hurley stage, the HS Sartorius score (HSS) and the active nodule (AN) count.

RESULTS

At the time of data lock, 73 patients with a confirmed diagnosis of HS were enrolled, and four (5.4%) had baseline positive ANA. None of the patients had clinical evidence of systemic lupus erythematosus or other autoimmune diseases. There were no significant differences in demographics, baseline HSS (43.25 ± 47.55 compared to 59.48 ± 56.67, P = 0.58) or AN count (3.25 ± 3.20 compared to 3.45 ± 2.36, P = 0.87) in the ANA positive group. Of the 69 patients who were ANA negative at enrollment, 31 (45%) received TNF-α inhibitor therapy. During follow up, one patient developed drug-induced lupus secondary to TNF-α inhibitor use. Additionally, one patient seroconverted to ANA positive without sequelae and one patient developed drug-induced hepatitis secondary to TNF-α inhibitor use.

CONCLUSION

The prevalence of baseline ANA positivity in this HS population was similar to that seen in the general population (5.4%). The rate of seroconversion and drug-induced complications in this population were low.

Prevalence of positive QuantiFERON gold in-tube testing in hidradenitis suppurativa

AIM

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory disease of the apocrine sweat glands. Tumor necrosis factor-alpha (TNF-α) inhibitors are commonly used to treat HS. However, prior to initiating therapy patients must be screened for mycobacterium tuberculosis (mTB) exposure. Several mTB screening tests based on interferon gamma release assays are commercially available, but the performance of these assays in the HS population is unknown. The purpose of this study was to investigate the performance of the QuantiFERON gold in-tube assay (QFT-GIT) in a cohort of patients with HS.

METHODS

This prospective study was conducted through the Wound Etiology and Healing (WE-HEAL) study. QFTGIT testing was performed using a commercial laboratory. Patients with positive test results underwent follow-up testing to evaluate for latent tuberculosis infection (LTBI). Data were collected on demographics and disease activity scores including Hurley stage, HS Sartorius score (HSS) and active nodule (AN) count.

RESULTS

Of the 69 patients with a confirmed diagnosis of HS, seven (10.1%) tested QFT-GIT positive and 5.8% were diagnosed with LTBI.

CONCLUSIONS

QFT-GIT results did not correlate with demographic characteristics or HS disease activity.

Longitudinal observational study of hidradenitis suppurativa: impact of surgical intervention with adjunctive biologic therapy

BACKGROUND

Hidradenitis supppurativa (HS) is a chronic inflammatory disease of the apocrine sweat glands affecting 1-4% of the population. While surgical excision is a mainstay of therapy, lesions often recur. Biologic therapies, including tumor necrosis factor-α and IL-12/23 inhibitors, are effective for mild to moderate HS. However, longitudinal studies investigating biologic therapy in conjunction with surgery are limited. The purpose of this analysis was to investigate impact of surgery and biologic therapy on HS disease activity.

METHODS

Data from 68 HS patients were analyzed. Outcome measures included hidradenitis suppurativa Sartorius Score (HSS), active nodule (AN) count, Hurley stage, and probability of achieving 75% reduction in active nodule count (AN75).

RESULTS

Mean age was 40 ± 14 years; 66% were female and 72% were African American. Mean disease duration was 10 years, and Hurley stage III disease was seen in 63% of patients. Patients who received biologics had a larger drop in HSS and AN count than those who never received biologics (P = 0.002). Biologic treatment was associated with average reduction in 22 (15-29) HSS points (P < 0.0001). The effect of biologics was greater in patients who also underwent surgery (P = 0.013). Timing of biologics relative to surgery did not impact efficacy. Patients who received HS surgery with biologic therapy were most likely to achieve the AN75 (P = 0.017).

CONCLUSIONS

In this diverse cohort of patients with severe HS, biologic therapy was associated with a more rapid decline in disease activity, with the greatest effect in patients who also underwent HS surgery.

The Contribution of Malodour in Quality of Life of Patients With Hidradenitis Suppurativa

Background:

Malodourous discharge in patients with hidradenitis suppurativa (HS) has a strong psychosocial impact and is often reported as a source of embarrassment, low self-esteem, social stigma, and barriers to interpersonal relationships. Malodour is a maker of bacterial colonization, and its role in HS is understudied.

Objectives:

The aim of this study is to assess the relationship between severity of malodourous discharge and quality-of-life impairment in patients with HS.

Methods:

This is a cross-sectional study of 51 patients recruited from the Women’s College Hospital and the York Dermatology Centre. Quality of life was assessed using both the Dermatology Life Quality Index (DLQI) and the Skindex-29 instruments.

Results:

Severity of odour significantly predicts the total Skindex score after controlling for disease severity as measured by the Hurley stage and Sartorius score ( R2 = 0.39, F = 8.11, P < .0001). However, odour severity is not a predictor of DLQI ( R2 = 0.17, F = 2.63, P = .064). There was no difference in mean DLQI scores for the low- vs high-odour groups, but patients with high odour had a greater quality of life impairment as measured by the Skindex tool ( t = −4.19, df = 43, P < .0001, mean difference = −18.87).

Conclusion:

Malodour is a common symptom that significantly impairs quality of life in patients with HS. The fact that this effect is captured in Skindex and not the DLQI may be attributed to the nonspecificity of the DLQI in terms of unique disease characteristics. It is important to address odour in the management of patients with HS.

Development and validation of the International Hidradenitis Suppurativa Severity Score System (IHS4), a novel dynamic scoring system to assess HS severity

BACKGROUND

A validated tool for the dynamic severity assessment of hidradenitis suppurativa/acne inversa (HS) is lacking.

OBJECTIVES

To develop and validate a novel dynamic scoring system to assess the severity of HS.

METHODS

A Delphi voting procedure was conducted among the members of the European Hidradenitis Suppurativa Foundation (EHSF) to achieve consensus towards an initial HS Severity Score System (HS4). Strengths and weaknesses of HS4 were examined by a multicentre prospective study. Multivariate logistic regression, discriminant analysis and receiver operating characteristic curves, as well as examination for correlation (Spearman's rho) and agreement (Cohen's kappa) with existing scores, were engaged to recognize the variables for a new International HS4 (IHS4) that was established by a second Delphi round.

RESULTS

Consensus HS4 was based on number of skin lesions, number of skin areas involved and Dermatology Life Quality Index (DLQI), and was evaluated by a sample of 236 patients from 11 centres. Subsequently, a multivariate regression model calculated adjusted odds ratios for several clinical signs. Nodules, abscesses and draining tunnels resulted as the scoring variables. Three candidate scores were presented to the second Delphi round. The resulting IHS4 score is arrived at by the number of nodules (multiplied by 1) plus the number of abscesses (multiplied by 2) plus the number of draining tunnels (multiplied by 4). A total score of 3 or less signifies mild, 4-10 signifies moderate and 11 or higher signifies severe disease. Cohen's kappa was fair (κ = 0·32) compared with Hurley classification, and moderate (κ = 0·49) compared with Expert Opinion. Correlation was good (ρ > 0·6) with Hurley classification, Expert Opinion, Physician's Global Assessment and Modified Sartorius score, and moderate for DLQI (ρ = 0·36).

CONCLUSIONS

The novel IHS4 is a validated tool to dynamically assess HS severity and can be used both in real-life and the clinical trials setting.

Ultrasound Evaluation as a Complementary Test in Hidradenitis Suppurativa: Proposal of a Standarized Report

BACKGROUND

Staging and monitoring of patients with hidradenitis suppurativa (HS) have been traditionally based on clinical findings. However, the physical examination may show important limitations because of its poor sensitivity for differentiating between different lesion subtypes, and its low sensitivity to define the disease's activity.

OBJECTIVE

To develop a consensus ultrasound (US) report that could summarize the relevant anatomical characteristics and staging of patients considering the experience of radiologists and dermatologists working on imaging of HS.

METHODS

A questionnaire on different aspects related to US examination in HS was performed. A working group, called DERMUS, composed of doctors from 9 countries who have been working in dermatologic US applied in patients with HS on a regular basis were included to evaluate the different items provided.

RESULTS

A consensus US report to evaluate HS patients was established.

CONCLUSION

The authors present the first attempt to define a HS standardized sonographic report. This model would be the first effort to include this imaging technique as the first elective medical test for staging and monitoring patients, which can support therapeutic decisions by providing earlier, objective, deeper, anatomical, and comparative evaluations in this difficult to treat disease.

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.

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.).

Protocol for the development of a core domain set for hidradenitis suppurativa trial outcomes

INTRODUCTION

Randomised controlled trials (RCTs) should have well-defined primary and secondary outcomes to answer questions generated by the main hypotheses. However, for the chronic, inflammatory skin disease hidradenitis suppurativa (HS), the reported outcome measures are numerous and diverse. A recent systematic review found a total of 30 outcome measure instruments in 12 RCTs. This use of a broad range of outcome measures can increase difficulties in interpretation and comparison of results and may potentially obstruct appropriate evidence synthesis by causing reporting bias. One strategy for dealing with these problems is to develop a core outcome set (COS). A COS is a list of outcomes that are meant as mandatory and should be measured and reported in all clinical trials. The aim of this study is to develop a COS for the management of HS.

METHOD AND ANALYSIS

An international steering group of researchers, clinicians and a patient research partner will guide the COS development. 6 stakeholder groups are involved: patients, dermatologists, surgeons, nurses, industry representatives and drug regulatory authorities. A 1:1 ratio of patients:healthcare professionals is aimed for. The initial list of candidate items will be obtained by combining three data sets: (1) a systematic review of the literature, (2) US and Danish qualitative interview studies involving patients with HS and (3) an online healthcare professional (HCP) item generation survey. To reach consensus on the COS, 4 anonymous online Delphi rounds are then planned together with 2 face-to-face consensus meetings (1 in Europe and 1 in the USA) to ensure global representation.

ETHICS AND DISSEMINATION

The study will be performed according to the Helsinki declaration. All results from the study, including inconclusive or negative results, will be published in peer-reviewed indexed journals. The study will involve different stakeholder groups to ensure that the developed COS will be suitable and well accepted.

Interferon-gamma (IFN-γ) is Elevated in Wound Exudate from Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic recurrent inflammatory disease of apocrine glands which affects 1-4% of young adults. The purpose of this study was to investigate inflammatory cytokines in effluent from HS lesions and to identify potential local drivers of inflammation in HS. Wound fluid specimens from HS patients (n = 8) and age-matched chronic wound patients (n = 8) were selected for analysis. The hidradenitis suppurativa score (HSS) was used to determine the extent of HS activity. Cytokine analysis was conducted using Meso Scale Discovery cytokine and proinflammatory panels. Interferon-gamma (IFN-γ) was significantly elevated in the HS effluent compared to chronic wounds (1418 ± 1501 pg/ml compared to 102.5 ± 138 pg/ml, p = 0.027). HS effluent also had significantly higher levels of tumor necrosis factor-β (TNF-β) (9.24 ± 7.22 pg/ml compared to 1.65 ± 2.14 pg/ml, p = 0.03). There was no significant difference in any other cytokines. There was no significant difference in demographics in the HS compared to chronic wound cohorts. Mean HSS in the HS cohort was 68.88 (SD ± 41.45). In this proof-of-concept pilot study, IFN-γ was significantly elevated in HS effluent. TNF-β/LT-α levels were also elevated in HS, although the levels were more modest. Further studies should focus on molecular drivers of tissue injury in HS and the relationship between HS effluent cytokine profile and disease activity.

The effect of smoking and age on the response to first-line therapy of hidradenitis suppurativa: An institutional retrospective cohort study

BACKGROUND

Treatment for hidradenitis suppurativa is often empiric and inadequate, and determining which patients will respond is difficult.

OBJECTIVE

We sought to determine which patient factors are associated with a positive response to first-line medical therapy.

METHODS

A single-center retrospective cohort study of all patients with hidradenitis suppurativa seen between January 1, 1992, and October 1, 2014, was conducted. Response to first-line medical therapy (oral/topical antibiotics, intralesional corticosteroids, and topical washes) was examined at follow-up within 6 months of initiating therapy. A multivariate binary logistic regression model was built examining response to treatment and the interplay of patient factors and treatment initiated.

RESULTS

In all, 198 patients were included in the final model. Nonsmokers (odds ratio 2.634, 95% confidence interval 1.301-5.332, P = .007) and older individuals (odds ratio 1.046 for each additional year, 95% confidence interval 1.020-1.072, P < .001) were more likely to have improvement at follow-up. In addition, current smokers differed significantly from nonsmokers in several regards.

LIMITATIONS

The retrospective nature of this study is a limitation, as is relying on classification of disease severity from physical examination findings in some patients.

CONCLUSIONS

The results of this study suggest that clinicians may be able to more accurately predict which patients with hidradenitis suppurativa will respond to first-line medical therapy, and which patients may require therapy escalation.

Imaging of Hidradenitis Suppurativa

Hidradenitis suppurativa is a complex disease of chronic evolution and difficult management. Imaging, particularly color Doppler ultrasound, has demonstrated a wide range of subclinical anatomic abnormalities, allowing modification of the clinical assessment of severity of the disease and therefore management of patients. Sonography supports early and more precise diagnosis and staging by providing critical objective information in real time. The richness of these data can also support assessment of the pathogenesis of the disease, allow monitoring of patients, and contribute to clinical trials. MRI can support the diagnosis of extensive anogenital and deep lesions.

Diagnosing Hidradenitis Suppurativa

Three diagnostic criteria must be met for hidradenitis suppurativa: typical lesions, occurrence in one or more of the predilection areas, and that it is chronic and/or recurrent. Several outcome measures are used, including patient-reported pain and itch scales, Dermatology Life Quality Index, and Skindex. Hidradenitis suppurativa is associated with significant comorbidities that must be addressed in the evaluation of the patients.

New insights into the diagnosis of hidradenitis suppurativa: Clinical presentations and phenotypes

Current classifications for hidradenitis suppurativa (HS), such as the Hurley staging system, are not very specific. The absence of rigorous classifications is incongruous with the clinical variability of the condition. There is no pathognomonic sign for HS that leads to a diagnosis that is unquestionable. Consequently, diagnosis is made largely through clinical presentation of the condition. The use of several validated tools assists in confirming the diagnosis and the severity of the disease. In future investigations, the identification of phenotypes and clinical subtypes--taking into account genetic variants--will serve to identify subpopulations of patients who are responsive to particular therapies, thereby improving the overall therapeutic picture for patients with HS. There is a potential for personalized, tailored delivery of therapy in the HS setting.

Interventions for hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition characterised by recurrent painful boils in flexural sites, such as the axillae and groin, that affects about 1% of the population, with onset in early adulthood.

OBJECTIVES

To assess the effects of interventions for HS in people of all ages.

SEARCH METHODS

We searched the following databases up to 13 August 2015: the Cochrane Skin Group Specialised Register, CENTRAL in the Cochrane Library (Issue 7, 2015), MEDLINE (from 1946), EMBASE (from 1974), and LILACS (from 1982). We also searched five trials registers and handsearched the conference proceedings of eight dermatology meetings. We checked the reference lists of included and excluded studies for further references to relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of all interventions for hidradenitis suppurativa.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and methodological quality and performed data extraction. Our primary outcomes were quality of life, measured by a validated dermatology-specific scale, and adverse effects of the interventions.

MAIN RESULTS

Twelve trials, with 615 participants, met our inclusion criteria. The median number of participants in each trial was 27, and median trial duration was 16 weeks. The included studies were conducted over a 32-year time period, from 1983 to 2015. A single RCT that was underpowered to detect clinically meaningful differences investigated most interventions.There were four trials of anti-TNF-α (tumour necrosis factor-alpha) therapies, which included etanercept, infliximab, and adalimumab. Adalimumab 40 mg weekly improved the Dermatology Life Quality Index (DLQI) score in participants with moderate to severe HS by 4.0 points relative to placebo (95% confidence interval (CI) -6.5 to -1.5 points), an effect size approximately equal to the DLQI minimal clinically important difference. We reduced the evidence quality to 'moderate' because the effect size was based on the results of only one study. In a meta-analysis of two studies with 124 participants, standard dose adalimumab 40 mg every other week was ineffective compared with placebo (moderate quality evidence). In a smaller study of 38 participants, of whom only 33 provided efficacy data, infliximab 5 mg/kg treatment improved DLQI by 8.4 DLQI points after eight weeks. Etanercept 50 mg twice weekly was well tolerated but ineffective.In a RCT of 200 participants, no difference was found in surgical complications (week one: risk ratio (RR) 0.78, 95% CI 0.58 to 1.05, moderate quality evidence) or risk of recurrence (after three months: RR 0.96, 95% CI 0.68 to 1.34, moderate quality evidence) in those randomised to receive a gentamicin-collagen sponge prior to primary closure compared with primary closure alone.RCTs of other interventions, including topical clindamycin 1% solution; oral tetracycline; oral ethinylestradiol 50 mcg with either cyproterone acetate 50 mg or norgestrel 500 mcg; intense pulsed light; neodymium-doped yttrium aluminium garnet (Nd:YAG) laser; methylene blue gel photodynamic therapy; and staphage lysate, were relatively small studies, preventing firm conclusions due to imprecision.

AUTHORS' CONCLUSIONS

Many knowledge gaps exist in RCT evidence for HS. Moderate quality evidence exists for adalimumab, which improves DLQI score when 40 mg is given weekly, twice the standard psoriasis dose. However, the 95% confidence interval includes an effect size of only 1.5 DLQI points, which may not be clinically relevant, and the safety profile of weekly dosing has not been fully established. Infliximab also improves quality of life, based on moderate quality evidence.More RCTs are needed in most areas of HS care, particularly oral treatments and the type and timing of surgical procedures. Outcomes should be validated, ideally, including a minimal clinically important difference for HS.

The Hidradenitis Suppurativa Priority Setting Partnership

BACKGROUND

Hidradenitis suppurativa (HS) has been neglected by medical researchers and society in general, despite being a relatively common, painful, chronic skin disease.

OBJECTIVES

To generate a top 10 list of HS research priorities, from the perspectives of patients with HS, carers and clinicians, to take to funding bodies.

METHODS

A priority setting partnership was established between patients with HS, carers and clinicians, following the James Lind Alliance process. Survey 1 requested submission of HS uncertainties, which were grouped into 'indicative uncertainties' for prioritization in survey 2. The 30 highest-ranked indicative uncertainties were reduced to a 'top 10' list using nominal group technique at a prioritization workshop attended by all relevant HS stakeholders.

RESULTS

In total 1495 potential uncertainties were submitted in survey 1, including 57% from patients with HS and carers, and grouped into 55 indicative uncertainties. Ranking in survey 2 was completed by 371 participants, 50% of whom were patients and carers. The final workshop was attended by 22 HS stakeholders and four facilitators and produced a top 10 list, the three highest priorities in descending order being (i) What is the most effective and safe group of oral treatments in treating HS? (ii) What is the best management of an acute flare? (iii)What is the impact of HS and its treatment on people with HS?

CONCLUSIONS

The top 10 HS research priorities have been directly disseminated to funders to raise awareness of HS. The next step is to generate research questions that will provide the evidence needed to improve care for patients with HS.

Ultrasound in-depth characterization and staging of hidradenitis suppurativa

BACKGROUND

The clinical diagnosis of fistulous tracts and recurrent fluid collections in hidradenitis suppurativa (HS) may be complex. Information on subclinical involvement and grading of severity may improve management.

OBJECTIVE

To study HS lesions and evaluate the relevance of adding ultrasound (US) to the clinical examination.

METHODS AND MATERIALS

We reviewed the sonograms of consecutive patients with HS from January 1, 2010 to May 31, 2012. The abnormalities observed in the US examinations were organized, classified, and integrated into a clinical-sonographic scoring system (SOS-HS), to stage the disease.

RESULTS

Thirty-four patients with HS with a total of 142 lesional areas were evaluated. US findings included subclinical fluid collections in 76.4% of the patients, fistulous tracts in 29.4%, dermal pseudocysts in 70.6%, and widening of the hair follicles in 100%. Concordance with the clinical HS scoring performed by dermatologists showed a significant fair agreement (k = 0.30; p < .001); concordance of SOS-HS with clinical scores was acceptable but significantly lower (k = 0.27; p = .02) because clinical scores consistently underestimated disease stage and severity.

CONCLUSION

US examination of HS lesions provides anatomic information that is clinically unavailable. HS is possible to stage sonographically.

Acne inversa (Hidradenitis suppurativa): A review with a focus on pathogenesis and treatment

Acne inversa (AI) is a disabilitating chronic inflammatory disease with major negative impact on quality of life and significant co-morbidities. This is an important link to insights into immune dysfunction, which stimulated therapeutic approaches like tumor necrosis-α inhibitor therapy. This new off-label drug treatment is particularly beneficial when used in combination with wide excision of inflamed skin and subcutaneous tissue. Retinoids have been reported to be helpful in secondary prevention. The standard of therapy in advanced cases is surgery with wide excisions and healing by secondary intention. This treatment results in significant reduction of complaints and achieves satisfactory body contouring.

Identification of three hidradenitis suppurativa phenotypes: latent class analysis of a cross-sectional study

To identify the underlying subtypes of hidradenitis suppurativa (HS), we performed latent class analysis on prospective clinical data of 618 consecutive patients seen between 2002 and 2010. The median patient age was 31 years (Q1=26; Q3=38), median age at HS onset was 20 years (16-25), and median Sartorius score was 18 (11-19); 34.4% of patients were of Hurley stage II or III. A three-class model showed the best fit. Latent class 1 (LC1) patients (48%) had a high probability of breast and armpit lesions (0.74) and hypertrophic scars (0.41). LC2 patients (26%) had a high probability not only of breast and armpit lesions (0.96) but also of lesions in the ears, chest, back, or legs (0.55); follicular lesions (pilonidal sinus: 0.48; comedones: 0.74); severe acne (0.47); and a family history of HS (0.44). Compared with LC1 patients, LC2 patients were more often male (odds ratio, 4.6; 95% confidence interval, 3-7; P<0.001) and current smokers (2.2; 1.3-3.9; P=0.005), and had greater disease severity (odds ratio, 1.6; 1.3-1.9; P<0.001). LC3 was characterized by gluteal involvement (0.54), papules, and folliculitis (0.71). LC3 patients were less often obese (0.6; 0.3-0.95; P=0.03) and had less severe disease (0.9; 0.7-1.1; P<0.001). These three phenotypes ("axillary-mammary", "follicular", and "gluteal") may help stratify patients for clinical trials.

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.

Comparing treatment outcome of infliximab and adalimumab in patients with severe hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic relapsing skin disease. Recent studies have shown promising results of anti-tumor necrosis factor-alpha treatment.

OBJECTIVE

To compare the efficacy and safety of infliximab and adalimumab in the treatment of HS.

METHODS

A retrospective study was performed to compare 2 cohorts of 10 adult patients suffering from severe, recalcitrant HS. In 2005, 10 patients were treated with infliximab intravenous (i.v.) (3 infusions of 5 mg/kg at weeks 0, 2, and 6). In 2009, 10 other patients were treated in the same hospital with adalimumab subcutaneous (s.c.) 40 mg every other week. Both cohorts were followed up for 1 year using identical evaluation methods [Sartorius score, quality of life index, reduction of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), patient and doctor global assessment, and duration of efficacy].

RESULTS

Nineteen patients completed the study. In both groups, the severity of the HS diminished. Infliximab performed better in all aspects. The average Sartorius score was reduced to 54% of baseline for the infliximab group and 66% of baseline for the adalimumab group.

CONCLUSIONS

Adalimumab s.c. 40 mg every other week is less effective than infliximab i.v. 5 mg/kg at weeks 0, 2, and 6.

A double-blind placebo-controlled randomized trial of adalimumab in the treatment of hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) has an impact on patients' quality of life. Treatment of HS is generally unsatisfactory, thus new treatments are needed.

OBJECTIVES

To test the efficacy of adalimumab in HS.

METHODS

This was a prospective, randomized, double-blinded, placebo-controlled, two-centre clinical trial conducted in Denmark. Inclusion criteria were age above 18 years and a clinical diagnosis of moderate to severe HS defined as Hurley stage II or III for at least 6 months. The patients were randomized 1:2 (placebo/active). Actively treated patients received adalimumab 80 mg subcutaneously (s.c.) at baseline followed by 40 mg s.c. every other week for 12 weeks. Placebo-treated patients received identical-looking injections with no active ingredient. The medicine was dispensed in sequentially numbered computer-randomized containers. Participants, care givers and those assessing the outcomes were blinded to group assignment. The primary efficacy endpoints were changes in the HS scores (Sartorius and Hurley scoring systems). Secondary efficacy endpoints included changes in pain (visual analogue scale), days with lesions and Dermatology Life Quality Index, and evaluation of scarring. Recruitment was terminated early due to expiry date of trial medication.

RESULTS

Twenty-one patients were included, of whom 15 received adalimumab and six received placebo. All participants were analysed according to the intention to treat principle. A significant reduction was seen in Sartorius score after 6 weeks and an almost significant reduction was seen after 12 weeks of active treatment (-10·7 vs. 7·5, P = 0·024 and -11·3 vs. 5·8, P = 0·07) when compared with the placebo group.

CONCLUSIONS

A significant reduction in HS severity was gained after 6 weeks. No long-term curative effect was uniformly seen.