Identification of Clinical and Genetic Parameters Associated with Hidradenitis Suppurativa in Inflammatory Bowel Disease

A Review of Cutaneous Extraintestinal Manifestations of Inflammatory Bowel Disease in Skin of Color

The incidence of inflammatory bowel disease (IBD) is increasing in racial and ethnic minority groups. Cutaneous extraintestinal manifestations (EIMs) of IBD are well-known comorbid conditions that can occur in both active and quiescent IBD. Historically, cutaneous EIMs of IBD are described in White skin with a lack of literature describing these conditions in darker skin tones. This potentially creates a knowledge gap and awareness among providers in recognizing these conditions and offering therapy in a timely manner to non-White patients. This review aims to describe the cutaneous manifestations of IBD in a wide range of skin tones with several examples to improve awareness. With further awareness, this review will enable to provide equitable care to IBD patients with cutaneous EIMs.

Mucocutaneous manifestations of inflammatory bowel disease

Mucocutaneous manifestations can be indicative of a variety of gastrointestinal diseases, and the dermatologist needs to know how to recognize them to refer the right patients to the gastroenterologist. Conversely, the gastroenterologist is often confronted with mucocutaneous lesions that raise the question of a possible association with a known digestive disease. Among the extra-intestinal manifestations of inflammatory bowel disease (IBD), mucocutaneous manifestations are the most common. This review will provide a breakdown by classifying them into 4 groups: 1) reactive manifestations, which include neutrophilic dermatoses, aphthous stomatitis, erythema nodosum, and vasculitis; 2) Crohn's disease-specific granulomatous skin lesions, which are histologically characterized by tuberculoid granulomas similar to those found in the gastrointestinal tract; 3) nutritional deficiency manifestations secondary to anorexia, malabsorption, loss, and drug interactions; and 3) a variety of autonomous autoimmune or inflammatory skin diseases. Dermatologists may also be involved in the management of the adverse effects of IBD treatments, especially the so-called "paradoxical" psoriatic eruptions.

Single-Cell Transcriptomic and Targeted Genomic Profiling Adjusted for Inflammation and Therapy Bias Reveal CRTAM and PLCB1 as Novel Hub Genes for Anti-Tumor Necrosis Factor Alpha Therapy Response in Crohn's Disease

BACKGROUND

The lack of reliable biomarkers in response to anti-TNFα biologicals hinders personalized therapy for Crohn's disease (CD) patients. The motivation behind our study is to shift the paradigm of anti-TNFα biomarker discovery toward specific immune cell sub-populations using single-cell RNA sequencing and an innovative approach designed to uncover PBMCs gene expression signals, which may be masked due to the treatment or ongoing inflammation; Methods: The single-cell RNA sequencing was performed on PBMC samples from CD patients either naïve to biological therapy, in remission while on adalimumab, or while on ustekinumab but previously non-responsive to adalimumab. Sieves for stringent downstream gene selection consisted of gene ontology and independent cohort genomic profiling. Replication and meta-analyses were performed using publicly available raw RNA sequencing files of sorted immune cells and an association analysis summary. Machine learning, Mendelian randomization, and oligogenic risk score methods were deployed to validate DEGs highly relevant to anti-TNFα therapy response; Results: This study found PLCB1 in CD4+ T cells and CRTAM in double-negative T cells, which met the stringent statistical thresholds throughout the analyses. An additional assessment proved causal inference of both genes in response to anti-TNFα therapy; Conclusions: This study, jointly with an innovative design, uncovered novel candidate genes in the anti-TNFα response landscape of CD, potentially obscured by therapy or inflammation.

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

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

Causal association between inflammatory bowel disease and hidradenitis suppurativa: A two-sample bidirectional Mendelian randomization study

Background

Epidemiological studies have revealed a link between inflammatory bowel disease (IBD) and hidradenitis suppurativa (HS). To determine whether IBD and HS are causally related, we used the Mendelian randomization (MR) approach.

Methods

A two-sample MR was performed using an analysis of 12,882 patients and 21,770 controls with IBD and its main subtypes, ulcerative colitis (UC) and Crohn's disease (CD). A total of 409 cases and 211,139 controls without hidradenitis suppurativa (HS) were included in the data for this condition from various GWAS investigations. Odds ratios (ORs) with 95% confidence intervals (CIs) are used to estimate causal effects.

Results

The study assessed the causal relationship between HS and IBD in both directions. The risk of HS was increased by IBD (IVW OR = 1.34, 95% CI = 1.20-1.49, p = 2.15E-07) and, in addition, HS was affected by UC (IVW OR = 1.27, 95% CI = 1.13-1.43, p = 8.97E-04) and CD (IVW OR = 1.18, 95% CI = 1.08-1.29, p = 4.15E-04). However, there was no evidence of a causal relationship between HS and IBD or its subtypes (IBD IVW OR = 1.00, 95% CI = 0.96-1.05, p = 0.85; UC IVW OR = 0.99, 95% CI = 0.95-1.03, p = 0.65; CD IVW OR = 1.03, 95% CI = 0.98- 1.07, p = 0.28).

Conclusion

This study demonstrates that IBD and its subtypes have a causal effect on HS, whereas HS does not affect IBD. Gut-skin axis interactions may help to understand this association. Nevertheless, further studies are needed to clarify the pathophysiology of the causal relationship between IBD and HS.

New Insights in Hidradenitis Suppurativa from a Population-based Dutch Cohort: Prevalence, Smoking Behaviour, Socioeconomic Status and Comorbidities

Background

Hidradenitis suppurativa (HS) is a chronic autoinflammatory skin condition and is associated with several comorbidities. Previous studies report variable prevalence rates of HS, depending on the methodology. However, the exact prevalence remains unknown.

Objectives

To estimate the prevalence of HS in a large population‐based cohort in the Northern Netherlands, and to compare patients with HS to the general population, investigate characteristics and identify potential associated comorbidities.

Methods

Data were collected through a cross‐sectional survey‐based study within the Lifelines Cohort Study (n = 167 729), based on the general population located in the Northern Netherlands. A digital self‐reported questionnaire was developed consisting of validated questions for determining HS.

Results

Among 56 084 respondents, the overall prevalence of HS was 2.1% [95% confidence interval (CI) 2.0–2.2]. The respondents with HS had lower socioeconomic status than the controls (P < 0.001) and more frequently currently smoked (P < 0.001). Several new significant associations in patients with HS were revealed, such as fibromyalgia (OR 2.26, 95% CI 1.64–3.11), irritable bowel syndrome (OR 1.63, 95% CI 1.18–2.26), chronic fatigue syndrome (OR 1.72, 95% CI 1.06–2.78) and migraine (OR 1.48, 95% CI 1.11–1.96). Fibromyalgia and chronic fatigue syndrome remained significantly associated with HS in the multivariate analysis after adjusting for age, sex, body mass index, smoking status and socioeconomic status.

Conclusions

Our study showed a higher prevalence of HS in the Northern Netherlands compared with the overall estimated prevalence of 1% and identified several new associated comorbidities.

Risk Factors for Developing Hidradenitis Suppurativa in Patients With Inflammatory Bowel Disease: A Retrospective Case-Control Study

Background

Hidradenitis suppurativa (HS) is associated with inflammatory bowel disease (IBD), though risk factors remain to be determined.

Aim

To characterize HS among a cohort of IBD patients and identify risk factors for its development.

Methods

This was a retrospective case–control study at the ambulatory IBD centre at Mount Sinai Hospital from inception to May 2019. Patients with IBD who developed HS were included. Cases were matched 5:1 by age, gender (male versus female) and IBD type (ulcerative colitis [UC] or Crohn’s disease [CD]) to controls who had IBD without HS. Conditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs).

Results

Twenty-nine cases of HS (19 CD and 10 UC) and 145 controls were included. Of the 29 patients with HS, 11 (37.9%) were male and 18 (62.1%) were female. The severity of HS was mild in 10 (34.5%), moderate in 16 (55.2%) and severe in 3 (10.3%) patients. Patients with HS and IBD were more likely to be active (OR 10.3, 95% CI 2.0 to 54.0, P = 0.006) or past (OR 8.4, 95% CI 2.7 to 25.8, P < 0.005) smokers. Patients with HS and IBD were also more likely to have active endoscopic disease (OR 3.8, 95% CI 1.2 to 12.2, P = 0.022). Furthermore, those with HS and CD were more likely to have active perianal disease (OR 21.1, 95% CI 6.2 to 71.9, P < 0.005).

Conclusions

Active IBD, perianal disease and smoking may be associated with HS in IBD. Larger studies are needed to better characterize this morbid condition.

Association of hidradenitis suppurativa with Crohn’s disease

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disorder characterized by recurrent nodules, abscesses, and sinus tracts. Crohn’s disease (CD) is characterized by inflammation of the entire digestive tract and belongs to the group of inflammatory bowel diseases, and there are many extraintestinal manifestations, among which hidradenitis suppurativa is one of the rare extraintestinal manifestations. There appears to be a strong association between CD and HS based on clinical and histological similarities (sinus tract development, granulomatous inflammation, and scarring), intersections in pathogenesis (genetic loci, immune dysregulation mechanisms, and microbiome changes), and commonality in treatment. In this review, we summarize recent studies on the association between HS and CD.

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

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

The Temporal Relationships and Associations between Cutaneous Manifestations and Inflammatory Bowel Disease: A Nationwide Population-Based Cohort Study

The temporal relationships between inflammatory bowel disease (IBD)-associated cutaneous manifestations and IBD remain uncertain, with existing evidence mostly from separate cross-sectional studies. We sought to determine the risks of IBD-related dermatologic diseases before and after the diagnosis of IBD. We identified 2847 cases of IBD and 14,235 matched controls from the Taiwan National Health Insurance Research Database between 2003 and 2014. The risks of cutaneous manifestations before and after the diagnosis of IBD were estimated with multivariable-adjusted analyses. At diagnosis, IBD was associated with atopic dermatitis (odds ratio (OR) = 1.61; 95% confidence interval (CI), 1.14-2.28), erythema nodosum (OR = 7.44; 95%CI, 3.75-14.77), aphthous stomatitis (OR = 2.01; 95%CI, 1.72-2.35), polyarteritis nodosa (OR = 5.67; 95%CI, 2.69-11.98), rosacea (OR = 1.67, 95%CI = 1.19-2.35), and cutaneous T cell lymphoma (OR = 21.27; 95%CI, 2.37-191.00). IBD was associated with the subsequent development of pyoderma gangrenosum (hazard ratio (HR) = 17.79; 95%CI, 6.35-49.86), erythema nodosum (HR = 6.54; 95%CI, 2.83-15.13), polyarteritis nodosa (HR = 2.69; 95%CI, 1.05-6.90), hidradenitis suppurativa (HR = 2.48; 95%CI, 1.03-5.97), psoriasis (HR = 2.19; 95%CI, 1.27-3.79), rosacea (HR = 1.92; 95%CI, 1.39-2.65), and aphthous stomatitis (HR = 1.45; 95%CI, 1.22-1.72). This study clarified the associations and temporal relationships between cutaneous manifestations and IBD, highlighting the need for interdisciplinary care in the patient with specific dermatologic diseases presenting with abdominal symptoms, or the IBD patients with cutaneous lesions.

Omics data integration identifies ELOVL7 and MMD gene regions as novel loci for adalimumab response in patients with Crohn's disease

Response to anti-TNF therapy is of pivotal importance in patients with Crohn’s disease (CD). Here we integrated our and previously reported PBMC derived transcriptomic and genomic data for identification of biomarkers for discrimination between responders and non-responders to anti-TNF therapy. CD patients, who were naïve with respect to the treatment with biologicals, were enrolled in the study. DNA and RNA were extracted from peripheral blood mononuclear cells. RNA-seq was performed using BGISEQ-500. Genotyping was performed using Infinium Global Screening Array. Association regressions were carried out with 12 week response to adalimumab as an outcome variable. RNA-seq analysis confirmed 7 out of 65 previously suggested genes involved in anti-TNF response. Subsequently, analysis of single nucleotide variants in regions of confirmed genes identified 5 variants near MMD and two in ELOVL7 intronic regions associated with treatment response to anti-TNF. Functional analysis has shown that rs1465352, rs4422035 and rs78620886 are listed at H3K9ac_Pro histone modification epigenetic mark. The present study confirmed MMD and ELOVL7 involvement in anti-TNF response and revealed that the regulation of MMD and ELOVL7 gene regions in ADA response may be a part of a complex interplay extending from genetic to epigenetic and to transcriptomic level.

Prevalence of inflammatory bowel disease among pediatric patients with hidradenitis suppurativa and the potential role of screening with fecal calprotectin

BACKGROUND/OBJECTIVES

Previous studies have demonstrated an increased prevalence of inflammatory bowel disease (IBD) in adults with hidradenitis suppurativa (HS). Whether the same association exists in pediatric patients is unknown. Fecal calprotectin (FC) is used to screen and monitor disease activity in IBD. There are no data on using FC to screen for IBD in pediatric patients with HS. Study objectives include a) assessing the prevalence of IBD among pediatric patients with HS; b) characterizing the IBD phenotype among pediatric patients with HS; and c) describing the use of FC as a screening tool for IBD in this population.

DESIGN/METHODS

This retrospective chart review was conducted at a single academic children's hospital. We included patients ≤18 years old diagnosed with HS between 2013 and 2018.

RESULTS

We identified 109 pediatric patients with HS. Six patients (6/109, 5.5%) were diagnosed with IBD, 83.3% (5/6) classified as ulcerative colitis. Almost half (53/109, 48.6%) of HS patients had gastrointestinal symptoms; of those, 11.3% (6/53) were diagnosed with IBD. FC was obtained in 8.3% (9/109) of HS patients overall and 66.7% (4/6) of HS patients diagnosed with IBD. Among patients with gastrointestinal symptoms, FC was obtained in 17.0% (9/53); endoscopy was performed in 24.5% (13/53). FC was elevated in all patients with IBD with an FC level. Of those with elevated FC, 80.0% (4/5) had IBD.

CONCLUSIONS

Pediatric HS may be associated with an increased prevalence of IBD suggesting that more widespread screening for IBD may be indicated. FC is infrequently used but may be a useful screening tool.

Obesity is Not Associated With Need for Skin Grafting After Hidradenitis Excision

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic, debilitating disease associated with inflammation, recurrent abscesses, and fistulae of skin containing apocrine sweat glands. We hypothesize that the need for skin grafting after vacuum-assisted closure was decreased with increasing body mass index (BMI).

METHODS

Seventy-one consecutive patients with excisions for HS were retrospectively evaluated for demographic data, number of excisions, the total area of excised skin, need for skin grafting, and BMI. Patients were stratified for BMI and underwent logistic regression to compare all other variables.

RESULTS

Average for BMI was 30.8 ± 7.72, age was 36.89 ±13.52, area excised was 743 cm² ± 774 cm², mean operating room trips were 2.62 ± 1.59, and skin grafting was 0.52 ± 0.55. Patients were 60% male. Forty out of 71 patients were obese. There was no correlation between age, BMI, sex, thenumber of excisions, amount of skin excised, or need for a skin graft. There was a statistically significant relationship between the amount of skin excised and the need for skin grafting (P = .006).

CONCLUSIONS

The amount of skin affected by HS appears to be independent of patient BMI. The need for skin grafting is solely dependent upon the amount of tissue excised.

APPLICABILITY OF RESEARCH TO PRACTICE

This knowledge will help preoperative planning for all patients with HS, regardless of BMI.

Phenotypes and Pathophysiology of Syndromic Hidradenitis Suppurativa: Different Faces of the Same Disease? A Systematic Review

<b><i>Background:</i></b> There is growing evidence that (certain) hidradenitis suppurativa (HS) comorbidities comprise syndromes including HS as a key cutaneous manifestation. These apparently autoinflammatory syndromes and their diagnostic delay might have detrimental effects on affected patients. <b><i>Methods:</i></b> A systematic review was performed on the databases MEDLINE, EMBASE, and CENTRAL utilizing a standardized extraction form according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. <b><i>Results:</i></b> Sixty-four eligible articles on syndromic HS were retrieved. The identified syndromes included already described ones (pyoderma gangrenosum-acne-suppurative hidradenitis, pyogenic arthritis-pyoderma gangrenosum-acne-suppurative hidradenitis, psoriatic arthritis-pyoderma gangrenosum-acne-suppurative hidradenitis, pyoderma gangrenosum-acne vulgaris-hidradenitis suppurativa-ankylosing spondylitis, synovitis-acne-pustulosis-hyperostosis-osteitis) and further novel symptom constellations. Cutaneous signs, including HS lesions, usually precede signs from other organs. The cutaneous signs of a considerable proportion of patients appear refractory to conventional treatment, and monotherapy with biologics does not suffice to sustain remission. <b><i>Conclusion:</i></b> The results are subsequently discussed with focus on the pathophysiology and treatment of the detected syndromes. The dermatologist’s role in the precise diagnosis and early treatment administration of HS is pivotal. The purpose of the treatment should be the effective prevention or delay of the autoinflammatory march and its irreversible consequences.

Clinical management of the most common extra-intestinal manifestations in patients with inflammatory bowel disease focused on the joints, skin and eyes

Extra-intestinal manifestations (EIMs) of inflammatory bowel disease (IBD) occur frequently and contribute to morbidity and reduced quality of life. The musculoskeletal, ocular and cutaneous organ systems are frequently involved in IBD-related EIMs. By focusing on manifestations involving the joints, skin and eyes, this review will discuss the most common clinically relevant and burdensome EIMs that affect IBD patients, and strives for early recognition, adequate treatment and timely referral. For this purpose, we aimed to create a comprehensive overview on this topic, with the main focus on the treatment of reactive and associated EIMs, including spondyloarthropathies, pyoderma gangrenosum, erythema nodosum, psoriasis and anterior uveitis. The recently developed biologicals enable simultaneous treatment of inflammatory disorders. This review can be used as a helpful guide in daily clinical practice for physicians who are involved in the treatment of IBD patients.

Increased risk of permanent stoma in Crohn's disease associated with hidradenitis suppurativa: a case-control study

BACKGROUND

Crohn's disease (CD) and hidradenitis suppurativa (HS), a chronic inflammatory skin disease, induce similar inflammatory lesions of the groin and gluteal area. Both diseases are characterised by an inadequate immune response to commensal bacteria in genetically predisposed subjects and can be associated.

AIM

To assess whether HS was associated with clinical and prognostic factors in CD.

METHODS

A retrospective case-control study included 4645 patients with CD referred to Saint-Antoine Hospital gastroenterology tertiary care centre between 2003 and 2016. Matching variables were sex, age, age and the presence of perianal lesions at CD diagnosis, follow-up quality. HS was confirmed by dermatological examination; location, phenotype and severity (Hurley staging) were recorded.

RESULTS

Hidradenitis suppurativa prevalence was 0.95% (44 cases); 80% of patients displayed Hurley stage II or III disease. CD preceded HS in 70% of cases with a median interval of 9 years (IQR 5.25-12.75). CD with HS was more active (56% vs 40% years with active disease, P < 0.001) and required more anti-TNF agents (39% vs 23% years spent with anti-TNF treatment, P < 0.001) than CD without HS. HS was associated with a higher risk of permanent stoma, 16.8% (IQR 7.5-33.3) vs 2.5% (IQR 0.8-7.4) in the control group (P = 0.002). Multivariate analysis confirmed HS as independent risk factor for permanent stoma (odds ratio 6.19; 95% CI, 2.30-38.33; P < 0.001).

CONCLUSIONS

Hidradenitis suppurativa is associated with worse CD prognosis, more active disease and increased risk of permanent stoma, despite a higher use of anti-TNF agents.

Skin Manifestations in Pediatric Patients Treated With a TNF-Alpha Inhibitor for Inflammatory Bowel Disease: A Retrospective Study [Formula: see text]

BACKGROUND

Tumor necrosis factor (TNF) alpha inhibitors (anti-TNF) are effective in the treatment of inflammatory bowel disease (IBD) as well as psoriasis. Their increasing use has raised the identification of cutaneous side effects (CSEs). Evidence in children is limited.

OBJECTIVES

The objective of this study is to describe CSEs of anti-TNF treatment in a pediatric population with IBD.

METHODS

This is a retrospective single-center study of children with IBD under anti-TNF treatment between 2013 and 2016. A total of 40 patients with CSEs related to anti-TNF were referred to our pediatric dermatology clinic. A control group was randomly selected from patients receiving anti-TNF for IBD, who were referred to the dermatology clinic for other conditions unrelated to anti-TNF.

RESULTS

Of 343 patients with IBD, 40 (11.3%) presented CSEs potentially related to the treatment. No differences in sex, age, and underlying disease were found between those with and without CSEs. The most frequent CSEs were psoriasiform eruptions (41%) which were more exudative than usual, located especially in skin folds and on the scalp; skin infections (20%); and eczematous eruptions (10%). Only 5% of patients changed or discontinued the current anti-TNF because of CSEs.

CONCLUSION

This is one of the largest pediatric cohorts of IBD patients with CSEs. Psoriasiform eruptions were the most common CSEs, with predilection for skin folds and scalp, and frequent superimposed bacterial infection. Topical and/or systemic antibiotics were required in addition to topical corticosteroids in 25% of patients. The rate of discontinuation of anti-TNF therapy due to CSEs was low.

Overall and Subgroup Prevalence of Crohn Disease Among Patients With Hidradenitis Suppurativa: A Population-Based Analysis in the United States

Importance

Limited evidence supports a link between hidradenitis suppurativa (HS) and Crohn disease (CD), and this relationship has not been established in the United States.

Objective

To evaluate the prevalence of CD among patients with HS in the United States and to determine the strength of association between the 2 conditions.

Design, Setting, and Participants

Cross-sectional analysis of data from 51 340 patients with HS identified using electronic health records data in the Explorys multiple health system data analytics and research platform, which includes data from more than 50 million unique patients across all US census regions.

Main Outcomes and Measures

Primary outcome was diagnosis of CD.

Results

Of the 18 455 660 total population considered, 51 340 had HS (35 000 women). Of these patients with HS, 29 010 (56.5%) were aged 18 to 44 years; 17 580 (34,2%), 45 to 64 years; and 4750 (9.3%), 65 years or older. Prevalence of CD among patients with HS was 2.0% (1025/51 340), compared with 0.6% (113 360/18 404 260) among those without HS (P < .001). Prevalence of CD was greatest among patients with HS who were white (2.3%), aged 45 to 64 years (2.4%), nonobese (2.8%), and tobacco smokers (2.3%). In univariable and multivariable analyses, patients with HS had 3.29 (95% CI, 3.09-3.50) and 3.05 (95% CI, 2.87-3.25) times the odds of having CD, respectively, compared with patients without HS. Crohn disease was associated with HS across all patient subgroups. The association was strongest for men (OR, 3.61; 95% CI, 3.24-4.03), patients aged 45 to 64 years (OR, 3.49; 95% CI, 3.16-3.85), nonobese patients (OR, 4.09; 95% CI, 3.69-4.54), and nonsmokers (OR, 3.44; 95% CI, 3.10-3.82).

Conclusions and Relevance

These data suggest that patients with HS are at risk for CD. Gastrointestinal symptoms or signs suggestive of CD warrant additional evaluation by a gastroenterologist.

Association of Hidradenitis Suppurativa With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Importance

Hidradenitis suppurativa (HS) and inflammatory bowel disease (IBD) are inflammatory diseases that share common genetic susceptibility and immunologic features. However, the link between HS and IBD has been largely unclear.

Objective

To conduct a meta-analysis to investigate the association between HS and IBD.

Data Sources

A search of the MEDLINE, Cochrane Central Register of Controlled Trials, and Embase databases yielded 397 relevant studies from inception to June 10, 2018. Two additional studies were supplied by one of the investigators.

Study Selection

Case-control, cross-sectional, or cohort studies that examined the odds or risk of IBD in patients with HS were included. No geographic or language limitations were imposed.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. The Newcastle-Ottawa Scale was used to assess the risk of bias of included studies. Crohn disease and ulcerative colitis were analyzed separately, and a random-effects model meta-analysis was conducted.

Main Outcomes and Measures

The odds ratios (ORs) and hazard ratios (HRs) of IBD, Crohn disease, and ulcerative colitis in association with HS.

Results

Five case-control studies, 2 cross-sectional studies, and 1 cohort study with a total of 93 601 unique participants were included. The meta-analysis of case-control and cross-sectional studies showed significant associations of HS with Crohn disease (pooled OR, 2.12; 95% CI, 1.46-3.08) and ulcerative colitis (pooled OR, 1.51; 95% CI, 1.25-1.82). Two case-control studies found significant association of HS with IBD (ORs, 2.16 [95% CI, 1.40-3.34] and 10.00 [95% CI, 1.94-51.50]). One cohort study found an increased risk of IBD in patients with HS (HR, 5.6; 95% CI not reported; P < .002).

Conclusions and Relevance

The evidence to date supports an association of HS with IBD. These results suggest that consultation with gastroenterologists should be sought when patients with HS present with recurrent abdominal pain, chronic diarrhea, bloody stool, and body weight loss.

North American clinical management guidelines for hidradenitis suppurativa: A publication from the United States and Canadian Hidradenitis Suppurativa Foundations: Part I: Diagnosis, evaluation, and the use of complementary and procedural management

Hidradenitis suppurativa is a chronic inflammatory disorder affecting hair follicles, with profoundly negative impact on patient quality of life. Evidence informing ideal evaluation and management of patients with hidradenitis suppurativa is still sparse in many areas, but it has grown substantially in the last decade. Part I of this evidence-based guideline is presented to support health care practitioners as they select optimal management strategies, including diagnostic testing, comorbidity screening, and both complementary and procedural treatment options. Recommendations and evidence grading based on the evidence available at the time of the review are provided.

Diagnosis and treatment of dermatologic diseases in inflammatory bowel disease

PURPOSE OF REVIEW

Dermatologic manifestations in patients with inflammatory bowel disease (IBD) are increasingly recognized as related disorders, secondary to specific therapies used to treat IBD, or complications of IBD itself. These dermatologic manifestations can be difficult to manage.

RECENT FINDINGS

We summarize three categories of dermatologic manifestations in this review: extraintestinal cutaneous disorders, paradoxical manifestations to biologic therapies, and other drug-induced cutaneous manifestations. In particular, we provide current data surrounding clinical characteristics, epidemiology, and treatment modalities for individual cutaneous manifestations.

SUMMARY

Many extraintestinal cutaneous manifestations can be managed by optimized treatment of IBD itself, as shared treatment pathways exist. Paradoxical reactions to biologic agents may be driven by the individual biologic therapy. In these instances, if topical therapies or immunomodulators are not effective in treating the paradoxical cutaneous reaction, a change of class may be required. Nonmelanoma and melanoma skin cancers have been linked to specific therapies for IBD (including thiopurines and antitumor necrosis factor alpha agents, respectively). Therefore, optimizing preventive efforts towards skin cancer is warranted. Recognition of these cutaneous disorders by the practicing gastroenterologist is important, as is collaboration with dermatology for management of many cutaneous disorders.

High prevalence of hidradenitis suppurativa symptoms in axial spondyloarthritis patients: A possible new extra-articular manifestation

BACKGROUND

Spondyloarthritis (SpA), a chronic inflammatory, rheumatic disease, and hidradenitis suppurativa (HS), a chronic, debilitating, inflammatory skin disease, share several clinical and pathophysiological features, such as the association with inflammatory bowel disease and elevated cytokine levels IL-17 and TNF-α. Recently, SpA was reported to be more prevalent (2.3-28.2%) in patients with HS than in the general population. Conversely, the prevalence of HS in SpA is not exactly known.

OBJECTIVE

To determine the prevalence of HS in patients with axial SpA, a subtype of SpA primarily of the axial skeleton. Secondly, to identify patient characteristics associated with the presence of HS in axial SpA.

METHODS

In this cross-sectional study, a self-screening questionnaire based on validated diagnostic HS questions was sent to all participating axial SpA patients from the Groningen Leeuwarden Axial Spondyloarthritis (GLAS) cohort fulfilling the ASAS axial SpA criteria. Self-reported HS symptoms were confirmed by previous medical diagnosis or verification by phone using highly specific validated questions.

RESULTS

In total, 75.6% (449/592) questionnaires were eligible for analyses. Included patients had a mean age of 50 ± 13 years, 64% was male, mean symptom duration was 23 ± 13 years, and 79% was HLA-B27 positive. HS diagnosis could be confirmed in 41 patients, resulting in an estimated prevalence of 9.1%. In comparison to patients without a positive history of HS, these patients were more often female (54% vs. 35%, P = 0.02), showed higher axial SpA disease activity (mean BASDAI 4.5 vs. 3.6, p = 0.01 and ASDAS_CRP 2.6 vs. 2.2, P = 0.003) and worse quality of life (QoL) (median ASQoL 9.0 vs. 4.0, P < 0.001). Also, a history of heel enthesitis and dactylitis was more prevalent (34% vs. 19%, P = 0.03 and 15% vs. 6%, P = 0.05, respectively). Multivariable analysis showed that a higher score on ASDAS was independently associated with HS (OR: 1.639, 95% CI: 1.176-2.284).

CONCLUSION

In our cohort of axial SpA patients, HS is more prevalent than in the general population (9.1% versus 0.053-4.1%). HS is associated with female gender, lower QoL, and especially higher axial SpA disease activity.

Prevalence and Risk of Inflammatory Bowel Disease in Patients with Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease. In small studies, inflammatory bowel disease has been associated with the increased prevalence of HS, but the data on the concurrence of inflammatory bowel disease in patients with HS are limited. We therefore investigated the prevalence and risk of inflammatory bowel disease in patients with HS compared with the general population. The study linked all Danish individuals aged ≥18 years in nationwide registers. Adjusted odds ratios and adjusted hazard ratios were estimated by logistic regression and Cox regression, respectively. The study comprised 7,732 patients with HS and 4,354,137 subjects from the general population. The prevalence (HS vs. general population) was 0.8% and 0.3% (odds ratio 2.04; 1.59-2.62) for Crohn's disease and 1.3% and 0.7% (odds ratio 1.75; 1.44-2.13) for ulcerative colitis. The risk of new-onset Crohn's disease (hazard ratio 2.19; 1.44-3.34) and ulcerative colitis (hazard ratio 1.63; 1.18-2.27) was significantly increased among patients with HS. In conclusion, HS was significantly associated with the presence and risk of new-onset inflammatory bowel disease, although the prevalence remained low. Gastrointestinal complaints in patients with HS should warrant further clinical examination.

Inflammatory bowel disease is associated with hidradenitis suppurativa: Results from a multicenter cross-sectional study

BACKGROUND

Hidradenitis suppurativa (HS) is often associated with inflammatory bowel disease (IBD; Crohn's disease or ulcerative colitis). However, the prevalence of IBD in HS patients is unknown.

OBJECTIVE

To determine the prevalence of IBD in HS patients, and determine if patients with HS and IBD have a distinct HS phenotype.

METHODS

For this multicenter, cross-sectional study, HS patients were asked during their first consultation if they had IBD. The diagnosis of IBD was checked in the medical files, and clinical characteristics were collected.

RESULTS

IBD had a prevalence of 3.3% (95% CI 2.3-4.4) in 1076 HS patients. The prevalence of Crohn's disease was 2.5% (95% CI 1.6-3.4) and the prevalence of ulcerative colitis was 0.8% (95% CI 0.3-1.4). HS-IBD patients were less frequently obese (13.9% vs 31.2%, P = .04) than HS-only patients, but there were no differences in gender, family history of HS, disease severity, body areas affected by HS, or smoking status.

LIMITATIONS

The prevalence might be underestimated since HS patients might still develop IBD.

CONCLUSION

The prevalence of IBD in HS patients (3.3%) is 4-8 times higher than the prevalence in the general northern European population (0.41%-0.74%), however HS-IBD patients do not have a distinct HS phenotype.

Similar Depletion of Protective Faecalibacterium prausnitzii in Psoriasis and Inflammatory Bowel Disease, but not in Hidradenitis Suppurativa

BACKGROUND AND AIMS

Psoriasis and hidradenitis suppurativa [HS] co-occur more often with inflammatory bowel disease [IBD] than expected, due to shared pathogenic and genetic features. It is known that IBD patients harbour an altered intestinal microbiome characterised by a depletion of Faecalibacterium prausnitzii and increase of Escherichia coli. At present, it is unclear whether a similar intestinal microbiome trend can be identified in IBD-associated skin disorders. We therefore investigated the F. prausnitzii and E. coli abundance in psoriasis and HS, with and without concomitant IBD.

METHODS

Using quantitative polymerase chain reaction , we compared the F. prausnitzii and E. coli abundances in faecal samples from healthy controls [n = 33] with samples from patients with psoriasis [n = 29], IBD [n = 31], and concomitant IBD and psoriasis [n = 13]. Likewise, we analysed samples from patients with HS [n = 17], and concomitant IBD and HS [n = 17].

RESULTS

Psoriasis patients harboured a significantly lower abundance of F. prausnitzii in their stool than healthy controls [p < 0.001], which was similar to IBD patients. Together with the reduced F. prausnitzii levels, the psoriasis patients had a significantly higher abundance of E. coli [p < 0.001]. No significant difference in F. prausnitzii or E. coli abundance was found in HS. It was apparent that patients with concomitant IBD and associated skin disorder had the greatest decrease of F. prausnitzii and increase of E. coli.

CONCLUSIONS

The study demonstrates, for the first time, an IBD-like decrease of F. prausnitzii together with an increase of E.coli in psoriasis, supporting the presence of a gut-microbiome-skin axis in psoriasis and IBD.

Hydradenitis suppurativa and inflammatory bowel disease: An unusual, but existing association

Inflammatory bowel disease (IBD) could be associated with several extra-intestinal manifestations (EIMs) involving musculoskeletal, hepatopancreatobiliary, ocular, renal, and pulmonary systems, as well as the skin. In the last years, hidradenitis suppurativa (HS) is acquiring an increasing interest. IBD, especially Crohn’s disease (CD), is among the most reported associated diseases in HS patients. The aim of this paper is to give a brief overview of data showing a possible epidemiologic and pathogenetic association between IBD and HS. We performed a pooled-data analysis of four studies and pooled prevalence of HS in IBD patients was 12.8%, with a 95%CI of 11.7%-13.9%. HS was present in 17.3% of subjects with CD (95%CI: 15.5%-19.1%) and in 8.5% of UC patients (95%CI: 7.0%-9.9%). Some items, especially altered immune imbalance, are generally involved in IBD pathogenesis as well as invoked by HS. Smoking is one of the most relevant risk factors for both disorders, representing a predictor of their severity, despite, actually, there being a lack of studies analyzing a possible shared pathway. A role for inheritance in HS and CD pathogenesis has been supposed. Despite a genetic susceptibility having been demonstrated for both diseases, further studies are needed to investigate a genetic mutual route. Although the pathogenesis of IBD and HS is generally linked to alterations of the immune response, recent findings suggest a role for intestinal and skin microbiota, respectively. In detail, the frequent finding of Staphylococcus aureus and coagulase-negative staphylococci on HS cutaneous lesions suggests a bacterial involvement in disease pathogenesis. Moreover, microflora varies in the different cutaneous regions of the body and, consequently, two different profiles of HS patients have been identified on these bases. On the other hand, it is well-known that intestinal microbiota may be considered as “the explosive mixture” at the origin of IBD despite the exact relationship having not been completely clarified yet. A better comprehension of the role that some bacterial species play in the IBD pathogenesis may be essential to develop appropriate management strategies in the near future. A final point is represented by some similarities in the therapeutic management of HS and IBD, since they may be controlled by immunomodulatory drugs. In conclusion, an unregulated inflammation may cause the lesions typical of both HS and IBD, particularly when they coexist. However, this is still a largely unexplored field.