Harmonizing Hidradenitis Suppurativa: an Updated Glossary of Lesions with Clinical Presentations

Breast-feeding With Ectopic Axillary Breast Tissue

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

The impact of comorbidity identification on outcomes in patients with pyoderma gangrenosum: A retrospective cohort study of previously hospitalized patients

Crohn's disease (CD) is an inflammatory bowel disease (IBD) with major extraintestinal manifestations. Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that has previously been described to have a strong association with CD. Though the pathophysiology remains uncertain, this case series highlights the different aspects of disease presentation, similarities, severity, current treatment modalities, and the relational conflict between HS as a paradoxical side effect of biologic agents (BA) that is not well established.We identified a total of three patients with CD and HS and described their clinical presentation and management. A systematic search of the literature with PubMed and Ovid MEDLINE was done in 2021. Two patients were initially diagnosed with CD prior to developing skin manifestations. The third patient was diagnosed with HS first, then was found to have gastrointestinal symptoms. All patients had HS requiring surgical intervention. One patient failed a biological agent but responded to another. The second patient was treated with cytotoxic agents with acceptable results. The third patient was managed without the use of biologics. One of three patients’ clinical courses may suggest a paradoxical side effect of BA. The relationship between CD and HS is based on several case reports. A prospective study will help establish the relationship as well as shed light on the treatment of both conditions simultaneously. In addition, further evaluation of the causal relationship between BA, specifically adalimumab and infliximab as treatment for CD and HS are warranted to effectively manage Crohn’s disease, evaluate paradoxical HS, and improve outcomes of both HS and CD. CD and HS impact a patient's quality of life and physicians should therefore have a high degree of awareness upon diagnosis.

Hidradenitis suppurativa (HS) is a systemic disease with a strong association with inflammatory bowel disease (IBD) [1]. However, the relationship between HS and irritable bowel syndrome (IBS), a functional gastrointestinal disorder without underlying structural or inflammatory pathology, remains unclear [2]. One prior study (n = 160 patients) found IBS in 67.5% of HS patients and 28.8% of controls, but large-scale analyses are lacking [2]. Therefore, we designed a retrospective cohort study to evaluate IBS risk in HS patients using a real-world, multicenter database. Using the TriNetX Research Network, we conducted a retrospective cohort analysis evaluating adults (≥ 18) with and without HS. We queried codes from the 10th revision of the International Classification of Diseases (ICD-10) from October 14, 2015 to October 14, 2025 for HS (L73.2). IBS was defined as ≥ 2 ICD-10-CM recorded diagnoses for K58, a definition which has been previously validated [3]. Patients with IBD, celiac disease, microscopic colitis, colorectal cancer, cystic fibrosis, short bowel syndrome, small intestinal bacterial overgrowth, chronic pancreatitis, chemotherapy, or a history of major bowel surgery, at any point in their medical record, were excluded. Additionally, patients with IBS prior to their documented HS diagnosis were excluded. Lastly, patients with infectious gastroenteritis within 30 days prior to the study were excluded. Propensity score matching (1:1) was performed on age, demographics, and relevant comorbidities, including obesity, diabetes mellitus, tobacco use, gastroesophageal reflux disease, functional dyspepsia, anxiety, depression, systemic antibiotic use, proton pump inhibitor use, and chronic opioid use (Table 1). We assessed risk ratios (RRs) and absolute risk differences (ARDs) for IBS at 1, 5, and 10 years after HS diagnosis. Statistical significance was defined as a p-value < 0.05. We identified 129,031 HS patients and 129,031 matched controls. At 1 year follow-up, the RR of IBS in HS patients was 1.13, with an ARD of 0.078% (p = 0.0134). By 5 years, RR was. 1.16, with ARD 0.23% (p < 0.0001) (Table 2). Lastly, at 10 years RR 1.17, with ARD 0.29% (p < 0.0001). Despite increased relative risk, ARDs translate to ~1, 2, or 3 excess cases per 1000 HS patients at 1, 5, and 10 years. These findings highlight the importance of interpreting relative risk estimates within the context of absolute risk and that statistical significance does not necessarily equate to meaningful clinical impact. Therefore, clinicians should be aware of this potential risk but interpret it cautiously, considering both the modest ARDs observed and the broader context of the patient's clinical presentation and comorbidities. This distinction between statistical and clinical significance is crucial to avoid overstating the relevance of relative risk alone. Nevertheless, the biological plausibility of this relationship is supported by evidence that HS and IBS may share common gut–skin axis mechanisms. These include intestinal dysbiosis, immune dysregulation with elevated proinflammatory cytokines, and overlapping metabolic and signaling pathways influenced by diet [4, 5]. Limitations of our study include its retrospective design and reliance on ICD-10 coding to identify IBS, a functional diagnosis that introduces the potential for diagnostic misclassification. Additional misclassification may have occurred due to symptomatic overlap between IBD and IBS, including early or atypical IBD presentations not yet formally diagnosed despite lifetime exclusion criteria, as well as the stronger established association of HS with IBD and the higher prevalence of IBS in the general population [2]. Residual confounding is also possible, as psychosocial stressors, socioeconomic status, dietary factors, and duration of medication exposures could not be directly measured or controlled within the TriNetX database. Further, patients with HS may have increased healthcare utilization and greater exposure to medications such as antibiotics, proton pump inhibitors, and opioids, potentially introducing surveillance or detection bias that increases the likelihood of IBS diagnosis despite matching for these variables. The authors have nothing to report. No artificial intelligence (AI) or large language models were used in the writing, data analysis, figure/table creation, or editing of this manuscript. All text and analyses were conducted by the authors. Data accessible via TriNetX are presented in aggregate form and only contain anonymized data as per the deidentification standard defined by the US Health Insurance Portability and Accountability Act (HIPAA) in Section 164,514(a). Given this study used only de-identified data and did not involve individually identifiable patient data, this study was exempt from Institutional Review Board Approval. The authors declare no conflicts of interest. The data that support the findings of this study are available from TriNetX. Restrictions apply to the availability of these data, which were used under license for this study. Data are available from the author(s) with the permission of TriNetX.

International Journal of DermatologyEarly View Letter to the Editor Intralesional hyaluronidase as a treatment for fibrosis in hidradenitis suppurativa: a case report Recep Dursun, Recep Dursun [email protected] orcid.org/0000-0002-1279-574X Department of Dermatology, Necmettin Erbakan University Faculty of Medicine, Konya, TurkeySearch for more papers by this authorEsra Altay, Esra Altay [email protected] orcid.org/0009-0008-0418-8625 Department of Dermatology, Necmettin Erbakan University Faculty of Medicine, Konya, TurkeySearch for more papers by this authorSelami Aykut Temiz, Corresponding Author Selami Aykut Temiz [email protected] orcid.org/0000-0003-4878-0045 Department of Dermatology, Necmettin Erbakan University Faculty of Medicine, Konya, TurkeySearch for more papers by this author Recep Dursun, Recep Dursun [email protected] orcid.org/0000-0002-1279-574X Department of Dermatology, Necmettin Erbakan University Faculty of Medicine, Konya, TurkeySearch for more papers by this authorEsra Altay, Esra Altay [email protected] orcid.org/0009-0008-0418-8625 Department of Dermatology, Necmettin Erbakan University Faculty of Medicine, Konya, TurkeySearch for more papers by this authorSelami Aykut Temiz, Corresponding Author Selami Aykut Temiz [email protected] orcid.org/0000-0003-4878-0045 Department of Dermatology, Necmettin Erbakan University Faculty of Medicine, Konya, TurkeySearch for more papers by this author First published: 12 June 2024 https://doi.org/10.1111/ijd.17312 Conflict of interest: None. Funding source: None. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1Goldburg SR, Strober BE, Payette MJ. Hidradenitis suppurativa: epidemiology, clinical presentation, and pathogenesis. J Am Acad Dermatol. 2020; 82(5): 1045–1058. 10.1016/j.jaad.2019.08.090 CASPubMedWeb of Science®Google Scholar 2Sanchez J, Le Jan S, Muller C, François C, Renard Y, Durlach A, et al. Matrix remodelling and MMP expression/activation are associated with hidradenitis suppurativa skin inflammation. Exp Dermatol. 2019; 28(5): 593–600. 10.1111/exd.13919 CASPubMedWeb of Science®Google Scholar 3Wark KJ, Cains GD. The microbiome in hidradenitis suppurativa: a review. Dermatol Ther. 2021; 11: 39–52. 10.1007/s13555-020-00465-w Web of Science®Google Scholar 4Prens E, Deckers I. Pathophysiology of hidradenitis suppurativa: an update. J Am Acad Dermatol. 2015; 73(5): 8–11. 10.1016/j.jaad.2015.07.045 CASPubMedWeb of Science®Google Scholar 5Witte-Händel E, Wolk K, Tsaousi A, Irmer ML, Mößner R, Shomroni O, et al. The IL-1 pathway is hyperactive in hidradenitis suppurativa and contributes to skin infiltration and destruction. J Invest Dermatol. 2019; 139(6): 1294–1305. 10.1016/j.jid.2018.11.018 PubMedWeb of Science®Google Scholar 6Hamzavi IH, Griffith JL, Riyaz F, Hessam S, Bechara FG. Laser and light-based treatment options for hidradenitis suppurativa. J Am Acad Dermatol. 2015; 73(5 Suppl 1): S78–S81. https://doi.org/10.1016/j.jaad.2015.07.050 10.1016/j.jaad.2015.07.050 PubMedWeb of Science®Google Scholar 7Lindén O, Lönndahl L, Erlendsson AM, Sandberg C, Killasli H. Effects of mixed-technology CO2 and Ga-As laser in patients with hidradenitis suppurativa-A case series. JAAD Case Rep. 2022; 30: 124–127. https://doi.org/10.1016/j.jdcr.2022.10.022 10.1016/j.jdcr.2022.10.022 PubMedGoogle Scholar 8Searle T, Ali FR, Al-Niaimi F. Hyaluronidase in dermatology: uses beyond hyaluronic acid fillers. J Drugs Dermatol. 2020; 19(10): 993–998. https://doi.org/10.36849/JDD.2020.5416 10.36849/JDD.2020.5416 PubMedWeb of Science®Google Scholar 9Ibberson CB, Parlet CP, Kwiecinski J, Crosby HA, Meyerholz DK, Horswill AR. Hyaluronan modulation impacts Staphylococcus aureus biofilm infection. Infect Immun. 2016; 84(6): 1917–1929. 10.1128/IAI.01418-15 CASPubMedWeb of Science®Google Scholar Early ViewOnline Version of Record before inclusion in an issue ReferencesRelatedInformation

Experience in patients with hidradenitis suppurativa and COVID-19 symptoms

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition with many unmet needs. It is characterized by significant clinical heterogeneity, which suggests that a diagnosis of HS captures multiple distinct disease entities and that research aimed at identifying medically relevant HS subtypes will improve its management. Precision medicine is an approach to disease management that uses information encoded in a patient's genome, and operationalized in clinical presentations and drug responses, to identify disease subtypes. Prior research aimed at identifying HS subtypes has largely focused on phenotypic classifications derived from clinical features of cutaneous lesions. Limitations of existing HS taxonomies emphasize a need for a more nuanced understanding of disease subtypes. Evidence that has emerged from initial genetic studies of HS suggests the presence of at least three HS subtypes, each of which has different clinical implications in terms of disease risks and drug responses. These preliminary findings are instructive in terms of expanding our definitions of HS phenotypes to not only include characteristics of skin lesions, but also disease comorbidities and molecular and cellular phenotypes. Here we provide a comprehensive review of HS phenotype and genotype knowledge, and propose a strategic framework for implementing precision medicine in HS management. Future research should focus on expanding phenotype assessments to include data on multiple scales. Iterative research designs performed with phenotype and genotype data from large diverse cohorts are needed to rigorously define clinically relevant HS subtypes.

Hidradenitis suppurativa (HS) is an inflammatory skin condition that presents with nodules or abscesses associated with sinus tracts. Inflammatory bowel diseases (IBD) are inflammatory gastrointestinal (GI) conditions presenting with irregular bowel movements. Although HS and IBDs may have similarities in their clinical presentation and pathophysiology, they can differ in their cutaneous manifestations. Both conditions are potentially caused by genetic changes in the human leukocyte antigen (HLA), cause skin inflammation, and are characterized by abscesses in the GI and sinus tracts. We sought to determine the extent of coincident IBD and HS and the associated risk factors. The Ovid Medline database was searched for all current literature on the correlations between HS and IBD. Articles were then included and removed according to specific inclusion and exclusion criteria, and a systematic review was performed on the remaining articles. Thirteen papers that met the inclusion and the exclusion criteria were selected, and after data collection, a significant correlation was found between the development of HS and IBD. Most of the articles reviewed stated that the corresponding association was a causal link between the two diseases. Furthermore, there were various risk factors and comorbidities associated with HS and the development of IBD, including smoking, obesity, perianal disease, and genetic predispositions such as HLA-B27 mutations. Studies show that there is a potential correlation with HS and IBDs. Additional research should to determine the genetic correlations between HS and IBDs and the underlying pathophysiological mechanism.

Introduction: Hidradenitis suppurativa (HS) is a chronic inflammatory debilitating disorder showing ethnic heterogeneity in its clinical presentation and associated comorbidities. However, data on East Asian populations remain scarce. Methods: We conducted a retrospective analysis of clinical records for patients with HS diagnosed between 2006 and 2022 at two tertiary referral hospitals in Taiwan. Age- and sex-matched reference individuals without HS (3:1 ratio) were randomly selected from dermatology outpatients. Association between comorbidities and HS were analyzed using conditional logistic regression, while logistic regression identified predictors for lesion distribution and disease severity. Results: A total of 512 patients with HS and 1,536 reference individuals were identified. Comorbidities independently associated with HS were obesity, smoking, and diabetes. Men had 4.2 times the odds of developing gluteal lesions but only 0.5 times the odds of axillary or inguinal involvement compared to women. Current smokers had 2.8 times the odds of gluteal involvement but 0.6 times the odds of having axillary lesions. A significant association was observed between obesity and axillary involvement. Advanced disease (Hurley stage II and III) was significantly associated with male sex, smoking, and axillary involvement. Conclusion: Our study highlights distinct lesion distribution in East Asian patients with HS. Male sex and active smoking could predict for gluteal involvement, while female sex and obesity for axillary involvement. Independent risk factors for advanced disease were male sex, smoking, and axillary involvement.

Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease. Although a prevalence estimate has been proposed, this is based largely on studies from Europe, USA, and Australia. As literature on HS is scarce beyond these populations, our knowledge on epidemiology and clinical presentation from these areas are limited. Summary: A narrative literature search was conducted on the PubMed Medline database on November 6th, 2023, to examine HS epidemiological data from Asia, Latin America, North America, Africa, and Oceania, excluding articles from Europe, USA, and Australia. Relevant data (e.g., prevalence, gender distribution, age, smoking status) were extracted. A total of 26 articles were included: three from Africa, four from Latin America, one from North America, 18 from Asia, and none from Oceania. Prevalence varied widely, from 0.41% in Brazil to 3.2% in Greenland. Female predominance was noted in Latin America and Greenland, while male predominance was observed in Asia. Smoking rates varied significantly, from 0% in Ghana to 93.8% in Greenland. Key Messages: (1) There is a notable lack in epidemiological HS data from large areas of the globe, particularly from Africa, Latin America, and Oceania. Further, significant heterogeneity in methodology and data reporting leads to inconsistencies in the comparability of the available data; (2) there are notable differences in gender distribution of HS across regions, with female predominance seen in Latin America and Greenland, while male predominance is more common in East Asia; (3) obesity and smoking, factors commonly described as risk factors for HS, where not consistently described across the studies, suggesting possible regional differences in risk factors; (4) it is crucial to encourage HS research globally to improve understanding, diagnosis, and treatment options for this significant disease.

Hidradenitis suppurativa (HS) is a chronic inflammatory disabling skin disease consisting of recurrent nodules, sinuses, fistulas and scarring involving the intertriginous regions. HS is often a therapeutic challenge and most treatments are off-label. A better understanding of aetiology and pathogenesis of HS may facilitate the development of effective treatment. Although the clinical presentation is strongly reminiscent of bacterial infection, the role of bacteria remains controversial. Studies have isolated an array of different bacteria specimens. Consistent findings of Gram-positive cocci and Gram-positive rods including Staphylococus aureus, coagulase-negative staphylococci (CoNS) and Corynebacterium species in deep tissue samples have been demonstrated in HS and may constitute a central target for the immune system. Efficacy of antibiotics, that is rifampicin, clindamycin or tetracycline, supports a microbial role in disease pathogenesis. However, these antibiotics also work as immunomodulators of especially T cells, and the underlying mechanisms may therefore be more complex. We performed a systematic review of previous studies investigating the bacterial flora in hidradenitis suppurativa. We searched PubMed, EMBASE, Royal Danish Library and Cochrane library (search date 11 December 2014). A total of 66 papers were identified and nine papers published between 1988 and 2014 matched our inclusion criteria, yielding bacteriological data of a total of 324 patients with HS (mean age 36.8years and female/male ratio 215/109). This overview of the bacteriology may aid researchers and physicians exploring the potential role of bacteria in HS. Furthermore, to stimulate a broader debate, we also present different viewpoints on the possible role of bacteria in HS.

The influence of gender and smoking on hidradenitis suppurativa

Hidradenitis suppurativa (HS) is an uncommon chronic inflammatory disease in children, characterized by painful abscesses and lesions. It has been associated with various autoimmune conditions, including inflammatory bowel diseases (IBDs) and rheumatologic disorders. We present a 13-year-old female with Hurley stage III HS, who developed macrophage activation syndrome (MAS). Clinical presentation and laboratory findings led to a diagnosis of systemic lupus erythematosus (SLE). Treatment with immunosuppressive therapy resulted in symptom resolution and clinical improvement. In addition, a case-based review was conducted to evaluate the patterns, clinical features and possible underlying mechanisms in the pediatric patients with HS and autoimmune diseases. Twenty pediatric cases were included with a median HS onset age of 15 years (IQR: 4 years). Among these, 55% were diagnosed with IBDs, followed by autoimmune arthritis and psoriasis (10% each). Treatment was individualized, with 95% receiving biologic agent and 55% receiving antimicrobials. This case and case-based review of literature highlight the potential overlap between HS and autoimmunity, especially SLE, in the pediatric population and emphasize the importance of proactive monitoring for coexisting autoimmune diseases in patients with HS, in order to facilitate early detection and effective management.

Background: Hidradenitis suppurativa (HS) is a persistent, recurring skin inflammatory condition linked to various comorbidities. Management involves antibiotics, hormone therapy, immune-modulating drugs, surgery, and treatment of comorbidities. The objectives of the study were to assess the comorbidities, clinical presentation subtypes, and applied treatment of patients with HS. Methods: Patients with HS who visited the Centre of Dermatovenereology at Vilnius University Hospital Santaros Klinikos in Lithuania underwent evaluation based on the guidelines of the European Hidradenitis Suppurativa Foundation Registry questionnaire. Results: The study included 49 patients, and 61.22% (n = 30) had comorbidities. A strong positive correlation was found between a family history of inflammatory diseases (69.38% (n = 34)) and the severity of HS according to Hurley stage (r = 0.71 p < 0.05). A statistically significant correlation (r = 0.944, p = 0.02) was found between metabolic comorbidities and Hurley stage. Patients on biologic treatment had a mean IHS4 of 7.38 at the beginning of treatment and 3.22 at follow-up (p < 0.05). For patients not on biologics, the initial IHS4 score was 6.21 and 5.42 at follow-up (p > 0.05). Conclusions: A family history of inflammatory diseases and metabolic comorbidities showed a strong correlation with HS severity. Treatment with biologics showed significant improvement in HS scores compared to systemic antibiotics.