Differences in hidradenitis suppurativa patterns of cutaneous involvement between sexes: Insights from a cross-sectional study.

Hidradenitis suppurativa is a chronic, inflammatory condition of the pilosebaceous unit in which patients manifest multiple, painful cutaneous nodules, abscesses and tunnels. These lesions are described to affect the intertriginous zones, however, the condition exhibits significant phenotypic variability. Such variability is influenced by the patients lifestyle, genetic predisposition and sex. In this cross-sectional study, we investigate sex differences in patterns of hidradenitis suppurativa skin involvement, specifically at site of first involvement and most bothersome cutaneous site of involvement.

Tertiary lymphoid structures sustain cutaneous B cell activity in hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a chronic skin condition affecting approximately 1% of the US population. HS skin lesions are highly inflammatory and characterized by a large immune infiltrate. While B cells and plasma cells comprise a major component of this immune milieu, the biology and the contribution of these cells in HS pathogenesis are unclear. We aimed to investigate the dynamics and microenvironmental interactions of B cells within cutaneous HS lesions. Combining histological analysis, single-cell RNA sequencing, and spatial transcriptomics profiling of HS lesions, we defined the tissue microenvironment relative to B cell activity within this disease. Our findings identified tertiary lymphoid structures (TLSs) within HS lesions and described organized interactions among T cells, B cells, antigen-presenting cells, and skin stroma. We found evidence that B cells within HS TLSs actively underwent maturation, including participation in germinal center reactions and class switch recombination. Moreover, skin stroma and accumulating T cells were primed to support the formation of TLSs and facilitate B cell recruitment during HS. Our data definitively demonstrated the presence of TLSs in lesional HS skin and point to ongoing cutaneous B cell maturation through class switch recombination and affinity maturation during disease progression in this inflamed nonlymphoid tissue.

Association between Hidradenitis Suppurativa and Abnormalities in Semen Parameters and Sexual Function: A Pilot Study.

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease affecting patients of reproductive age. Although HS shares risk factors with male infertility, only 1 epidemiological study has evaluated this association. To further evaluate this potential association, findings on semen and hormonal analysis, testicular ultrasound, and the International Index of Erectile Function (IIEF-15) were compared between 28 men attending a tertiary HS clinic during the period April 2019 to April 2021, and 44 healthy controls, spouses of infertile women undergoing semen evaluation before in vitro fertilization. Patients with HS were divided based on the absence or presence of gluteal and genital lesions. Patients with HS were younger than controls (median 27 vs 34 years, p < 0.0004) and had a higher proportion of smokers (86% vs 33%, p < 0.0001). Semen parameters in patients with gluteal-genital lesions, specifically those with severe scrotal involvement necessitating surgery, were lower than the WHO reference values and significantly lower than in patients without gluteal-genital lesions and controls. Erectile dysfunction was reported by 93% of patients with HS. These findings suggest that spermatogenesis and sexual function may be impaired in young men with HS. Therefore, multidisciplinary management of HS should include their evaluation to identify patients who might benefit from semen cryopreservation and sexual treatment.

Brodalumab for severe hidradenitis suppurativa: a case of clinico-radiologic improvement and literature review.

Hidradenitis suppurativa (HS) is a chronic autoinflammatory follicular disease, affecting body areas that are rich in apocrine glands. Moderate-to-severe HS may severely impair patients' quality of life also because the available therapies are often unsatisfactory. Several lines of evidence suggest that inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-17 play a pivotal role in the physiopathology of HS. TNF-α inhibitors have long been used with benefit in moderate-severe forms of HS. However, several monoclonal antibodies against IL-17 isoforms are currently being investigated for HS. We report the case of a 50-year-old man with long-standing HS and concomitant palmo-plantar psoriasis treated with brodalumab after failure of various TNF-α inhibitors. The HS lesions and the patient's quality of life improved steadily over time until week-136. Interestingly, the clinical benefit was confirmed by radiological improvement with MRI evaluation. Our case report demonstrates the long-term efficacy and safety of brodalumab in HS encouraging the use of drugs to inhibit the T helper-type 17 immune axis, especially in cases of HS refractory to therapy with TNF-α inhibitors.

Biology of Interleukin-17 and Novel Therapies for Hidradenitis Suppurativa.

Skin disorders affect ∼40% of the human population. One of the most debilitating cutaneous disorders is Hidradenitis suppurativa (HS), a noncommunicable chronic inflammatory disease with an estimated global prevalence of 0.4% to 2.5%. In January 2011, high levels of IL-17 were discovered in skin lesions of HS patients. In the following years, translational and clinical research led to a better understanding of the pathogenesis of HS. In June 2023, more than 12 years after the initial note, secukinumab, an anti-IL-17A monoclonal antibody, was approved for the treatment of moderate to severe HS. This is the next milestone in improving the treatment of these patients after the approval of the anti-TNF-α monoclonal antibody adalimumab in 2015. In this review article, we present the IL-17 pathway in HS and discuss the use of secukinumab as a therapeutic option for this disease. Our review starts with a description of the epidemiology, clinical features, etiology, and pathogenesis of HS. An overview of the IL-17/IL-17 receptor system in general and a detailed description of the known facts about the expression and action of IL-17 in HS follow. Afterward, we consider the results of clinical trials evaluating the safety and efficacy of IL-17 inhibitors in HS. Finally, a comparison is made between secukinumab and adalimumab and the characteristics of the patients that may be particularly suitable for each of these biologics are described.

Adalimumab-Induced Paradoxical Psoriasis Treated with Biologics Targeting the IL-17/IL-23 Axis in Patients with Hidradenitis Suppurativa.

BACKGROUND: Paradoxical psoriasis (PP) has been mainly described in patients receiving tumor necrosis factor-α (TNFα) inhibitors for inflammatory bowel disease or psoriasis vulgaris, while such data in the context of hidradenitis suppurativa (HS) are scarce. The purpose of this study was to demonstrate the course of PP and the underlying HS upon switching from adalimumab to a biologic agent targeting the interleukin (IL)-17/IL-23 axis. METHODS: The electronic medical database of the outpatient department for HS of a tertiary hospital for skin diseases was searched to identify patients with moderate-to-severe HS under treatment with adalimumab, who developed PP and were switched to biological therapy with an IL-17 or IL-23 inhibitor between February 2016 and January 2022. Disease assessment scores were evaluated at baseline, at time of PP development, as well as six and 12 months thereafter. RESULTS: Among the 83 patients who received adalimumab for the treatment of HS between February 2016 and January 2022, 10 patients (12%) developed paradoxical psoriasiform skin reactions after a median time of seven (range, 2-48) months. There were four females (40%) and six males (60%) with a median age of 42.5 (range, 33-56) years. Five patients presented with plaque psoriasis and five with palmoplantar pustulosis, while four had intertriginous and three nail involvement. In most of the patients, HS responded well to adalimumab at onset of PP. Eight patients were changed to secukinumab, one to ustekinumab, and one to risankizumab. HS further improved in all but 2 patients, one receiving secukinumab and one receiving risankizumab. In addition, all patients achieved improvement of PP. CONCLUSION: Despite the small number of patients, this study provides support that patients with adalimumab-induced PP may benefit from biologics targeting the IL-17/IL-23 axis. Further studies are needed to establish the optimal therapeutic strategy of the anti-TNFα-induced PP in the context of HS.

Genetic Variants Associated With Hidradenitis Suppurativa.

Importance: Hidradenitis suppurativa (HS) is a common and severely morbid chronic inflammatory skin disease that is reported to be highly heritable. However, the genetic understanding of HS is insufficient, and limited genome-wide association studies (GWASs) have been performed for HS, which have not identified significant risk loci. Objective: To identify genetic variants associated with HS and to shed light on the underlying genes and genetic mechanisms. Design, Setting, and Participants: This genetic association study recruited 753 patients with HS in the HS Program for Research and Care Excellence (HS ProCARE) at the University of North Carolina Department of Dermatology from August 2018 to July 2021. A GWAS was performed for 720 patients (after quality control) with controls from the Add Health study and then meta-analyzed with 2 large biobanks, UK Biobank (247 cases) and FinnGen (673 cases). Variants at 3 loci were tested for replication in the BioVU biobank (290 cases). Data analysis was performed from September 2021 to December 2022. Main Outcomes and Measures: Main outcome measures are loci identified, with association of P < 1 × 10-8 considered significant. Results: A total of 753 patients were recruited, with 720 included in the analysis. Mean (SD) age at symptom onset was 20.3 (10.57) years and at enrollment was 35.3 (13.52) years; 360 (50.0%) patients were Black, and 575 (79.7%) were female. In a meta-analysis of the 4 studies, 2 HS-associated loci were identified and replicated, with lead variants rs10512572 (P = 2.3 × 10-11) and rs17090189 (P = 2.1 × 10-8) near the SOX9 and KLF5 genes, respectively. Variants at these loci are located in enhancer regulatory elements detected in skin tissue. Conclusions and Relevance: In this genetic association study, common variants associated with HS located near the SOX9 and KLF5 genes were associated with risk of HS. These or other nearby genes may be associated with genetic risk of disease and the development of clinical features, such as cysts, comedones, and inflammatory tunnels, that are unique to HS. New insights into disease pathogenesis related to these genes may help predict disease progression and novel treatment approaches in the future.

The Effectiveness of Guselkumab in Patients With Hidradenitis Suppurativa Under Clinical Practice Conditions: A Spanish Multicentre Retrospective Study. / [Artículo traducido] Efectividad de guselkumab en pacientes con hidradenitis supurativa en condiciones de práctica clínica: estudio retrospectivo y multicéntrico en España.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic skin condition causing lesions in which high levels of interleukin (IL)-23 and T-helper17 cells are found. Adalimumab remains the only approved treatment. Guselkumab, an antibody targeting the p19 protein subunit of extracellular IL-23, is approved for the treatment of moderate-severe psoriasis, but evidence on its efficacy in treating HS is limited. OBJECTIVES: To assess the effectiveness and safety of guselkumab in treating moderate-severe HS under clinical practice conditions. METHODS: A multicentre retrospective observational study was carried out in 13 Spanish hospitals including adult HS patients treated with guselkumab within a compassionate use programme (March 2020-March 2022). Data referred to patient demographic and clinical characteristics at treatment initiation (baseline), patient-reported outcomes (Numerical Pain Rating Scale [NPRS] and Dermatology Life Quality Index [DLQI]), physician scores (International Hidradenitis Suppurativa Severity Score System [IHS4], HS Physical Global Score [HS-PGA] and Hidradenitis Suppurativa Clinical Response [HiSCR]) were recorded at baseline and at 16, 24, and 48weeks of treatment. RESULTS: A total of 69 patients were included. Most (84.10%) had severe HS (HurleyIII) and had been diagnosed for over ten years (58.80%). The patients had been subjected to multiple non-biological (mean: 3.56) or biological (mean: 1.78) therapies, and almost 90% of those treated with biologics had received adalimumab. A significant decrease in IHS4, HS-PGA, NPRS, and DLQI scores was observed from baseline to 48weeks of guselkumab treatment (all P<.01). HiSCR was achieved in 58.33% and 56.52% of the patients at 16 and 24weeks, respectively. Overall, 16 patients discontinued treatment, mostly due to inefficacy (n=7) or loss of efficacy (n=3). No serious adverse events were observed. CONCLUSIONS: Our results indicate that guselkumab may be a safe and effective therapeutic alternative for patients with severe HS that fail to respond to other biologics.

The Effectiveness of Guselkumab in Patients With Hidradenitis Suppurativa Under Clinical Practice Conditions: A Spanish Multicentre Retrospective Study.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic skin condition causing lesions in which high levels of interleukin (IL)-23 and T-helper 17 cells are found. Adalimumab remains the only approved treatment. Guselkumab, an antibody targeting the p19 protein subunit of extracellular IL-23, is approved for the treatment of moderate-severe psoriasis, but evidence on its efficacy in treating HS is limited. OBJECTIVES: To assess the effectiveness and safety of guselkumab in treating moderate-severe HS under clinical practice conditions. METHODS: A multicentre retrospective observational study was carried out in 13 Spanish Hospitals including adult HS patients treated with guselkumab within a compassionate use programme (March 2020-March 2022). Data referred to patient demographic and clinical characteristics at treatment initiation (baseline), patient-reported outcomes (Numerical Pain Rating Scale [NPRS] and Dermatology Life Quality Index [DLQI]), physician scores (International Hidradenitis Suppurativa Severity Score System [IHS4], HS Physical Global Score [HS-PGA] and Hidradenitis Suppurativa Clinical Response [HiSCR]) were recorded at baseline and at 16, 24, and 48 weeks of treatment. RESULTS: A total of 69 patients were included. Most (84.10%) had severe HS (Hurley III) and had been diagnosed for over ten years (58.80%). The patients had been subjected to multiple non-biological (mean 3.56) or biological (mean 1.78) therapies, and almost 90% of those treated with biologics had received adalimumab. A significant decrease in IHS4, HS-PGA, NPRS, and DLQI scores was observed from baseline to 48 weeks of guselkumab treatment (all p<0.01). HiSCR was achieved in 58.33% and 56.52% of the patients at 16 and 24 weeks, respectively. Overall, 16 patients discontinued treatment, mostly due to inefficacy (n=7) or loss of efficacy (n=3). No serious adverse events were observed. CONCLUSIONS: Our results indicate that guselkumab may be a safe and effective therapeutic alternative for patients with severe HS that fail to respond to other biologics.

The Essential Role of microRNAs in Inflammatory and Autoimmune Skin Diseases-A Review.

The etiopathogenesis of autoimmune skin diseases is complex and still not fully understood. The role of epigenetic factors is emphasized in the development of such diseases. MicroRNAs (miRNAs), a group of non-coding RNAs (ncRNAs-non-coding RNAs), are one of the important post-transcriptional epigenetic factors. miRNAs have a significant role in the regulation of the immune response by participating in the process of the differentiation and activation of B and T lymphocytes, macrophages, and dendritic cells. Recent advances in research on epigenetic factors have provided new insights into the pathogenesis and potential diagnostic and therapeutic targets of many pathologies. Numerous studies revealed a change in the expression of some microRNAs in inflammatory skin disorders, and the regulation of miRNA expression is a promising therapeutic goal. This review presents the state of the art regarding changes in the expression and role of miRNAs in inflammatory and autoimmune skin diseases, including psoriasis, atopic dermatitis, vitiligo, lichen planus, hidradenitis suppurativa, and autoimmune blistering diseases.

A centre-based ambulatory care concept for hidradenitis suppurativa improves disease activity, disease burden and patient satisfaction: results from the randomized controlled EsmAiL trial.

BACKGROUND: Hidradenitis suppurativa (HS) is an inflammatory disease of the inverse skin regions that occurs in young women, in particular, and affects approximately 1% of the population. Outpatient care is often inadequate and usually cannot prevent progression. OBJECTIVES: To evaluate in the EsmAiL ('Evaluation eines strukturierten und leitlinienbasierten multmodalen Versorgungskonzepts für Menschen mit Akne inversa') trial whether an innovative care concept can decrease disease activity and burden, and improve patient satisfaction. METHODS: EsmAiL was conducted as a two-arm, multicentre, prospective, randomized controlled trial that included 553 adults with HS. Inclusion criteria were a minimum of three inflammatory lesions and at least a moderate impact of the disease on quality of life. The control group (CG) remained under standard care, while patients in the intervention group (IG) were treated according to a trial-specific, multimodal concept. The primary endpoint was the absolute change in International Hidradenitis Suppurativa Severity Score System (IHS4). RESULTS: In total, 274 patients were randomized to the IG and 279 to the CG. Altogether, 377 attended the final assessment after 12 months of intervention. Participants in the IG (n = 203) achieved a mean improvement in IHS4 of 9.3 points, while the average decrease in IHS4 in patients in the CG (n = 174) was 5.7 points (P = 0.003). Patients treated under the new care concept also reported a statistically significantly higher decrease in pain, Dermatology Life Quality Index and Hospital Anxiety and Depression Scale scores compared with those in the CG (P < 0.001). Patient satisfaction was also statistically significantly higher in the IG compared with the CG (P < 0.001). CONCLUSIONS: The establishment of standardized treatment algorithms in so-called 'acne inversa centres' in the ambulatory setting has a substantial, positive impact on the course of HS and significantly improves patient satisfaction.

Hidradenitis suppurativa in Black and White patients - a clinical study.

OBJECTIVE: It is suggested that hidradenitis suppurativa (HS) is more prevalent and causes greater morbidity in Black patients than in White. Clinical data are however lacking. PATIENTS AND METHODS: We therefore describe HS risk factors, disease severity and clinical phenotypes in the Blacks and Whites. Patients referred for HS between 1984 and 2019 at the Johns Hopkins Hospital were identified using the Pathology Data System (PDS). Clinical and sociodemographic characteristics were extracted and the van der Zee & Jemec HS clinical phenotypes were recovered. RESULTS: A total of 278 patients were identified. Ethnically, 108 (38.8%) were White, and 170 (61.2%) Black. The following HS phenotypes were found: Regular (n=193, 69.4%), scarring folliculitis (n=40, 1.4%) frictional furuncle (11.2%), conglobata (n=9, 3.2%), syndromic (n=3, 1.1%) and ectopic (n=2, 0.7%). No statistically significant ethnic differences in clinical presentation were found. Blacks however had more severe diseases than Whites (p= 0.024 for trend). With multivariate logistic regression analysis, we found that male sex, disease duration, and smoking were independent predictors of regular HS phenotype. Major limitations are the limited number of cases studied and the lack of data regarding response to therapies. CONCLUSIONS: Demographics and phenotypical presentation of HS patients do not seem to be associated with Black ethnicity. However, there is a significant trend for Blacks to present with more Hurley stage 2 and 3 disease compared to White patients. It is speculated that ethnic differences are epiphenomena to social factors, highlighting the broader importance of ethnicity.

Blood T Helper Memory Cells: A Tool for Studying Skin Inflammation in HS?

Hidradenitis suppurativa (HS) is an inflammatory skin disease characterized by painful lesions on intertriginous body areas such as the axillary, inguinal, and perianal sites. Given the limited treatment options for HS, expanding our knowledge of its pathogenetic mechanisms is a prerequisite for novel therapeutic developments. T cells are assumed to play a crucial role in HS pathogenesis. However, it is currently unknown whether blood T cells show specific molecular alterations in HS. To address this, we studied the molecular profile of CD4+ memory T (Thmem) cells purified from the blood of patients with HS and matched healthy participants. About 2.0% and 1.9% of protein-coding transcripts were found to be up- and down-regulated in blood HS Thmem cells, respectively. These differentially expressed transcripts (DETs) are known to be involved in nucleoside triphosphate/nucleotide metabolic processes, mitochondrion organization, and oxidative phosphorylation. The detected down-regulation of transcripts involved in oxidative phosphorylation suggest a metabolic shift of HS Thmem cells towards glycolysis. The inclusion of transcriptome data from skin from HS patients and healthy participants in the analyses revealed that in HS skin lesions, the expression pattern of transcripts identified as DETs in blood HS Thmem cells was very similar to the expression pattern of the totality of protein-coding transcripts. Furthermore, there was no significant association between the extent of the expressional changes in the DETs of blood HS Thmem cells and the extent of the expressional changes in these transcripts in HS skin lesions compared to healthy donor skin. Additionally, a gene ontology enrichment analysis did not demonstrate any association of the DETs of blood HS Thmem cells with skin disorders. Instead, there were associations with different neurological diseases, non-alcoholic fatty liver disease, and thermogenesis. The levels of most DETs linked to neurological diseases showed a positive correlation to each other, suggesting common regulatory mechanisms. In summary, the transcriptomic changes in blood Thmem cells observed in patients with manifest cutaneous HS lesions do not appear to be characteristic of the molecular changes in the skin. Instead, they could be useful for studying comorbidities and identifying corresponding blood biomarkers in these patients.

Modulation of Disease-Associated Pathways in Hidradenitis Suppurativa by the Janus Kinase 1 Inhibitor Povorcitinib: Transcriptomic and Proteomic Analyses of Two Phase 2 Studies.

Janus kinase (JAK)/signal transducer and activator of transcription signaling (STAT) has been implicated in the pathophysiology of hidradenitis suppurativa (HS). This study evaluated treatment-related transcriptomic and proteomic changes in patients with moderate-to-severe HS treated with the investigational oral JAK1-selective inhibitor povorcitinib (INCB054707) in two phase 2 trials. Lesional skin punch biopsies (baseline and Week 8) were taken from active HS lesions of patients receiving povorcitinib (15 or 30 mg) once daily (QD) or a placebo. RNA-seq and gene set enrichment analyses were used to evaluate the effects of povorcitinib on differential gene expression among previously reported gene signatures from HS and wounded skin. The number of differentially expressed genes was the greatest in the 30 mg povorcitinib QD dose group, consistent with the published efficacy results. Notably, the genes impacted reflected JAK/STAT signaling transcripts downstream of TNF-α signaling, or those regulated by TGF-ß. Proteomic analyses were conducted on blood samples obtained at baseline and Weeks 4 and 8 from patients receiving povorcitinib (15, 30, 60, or 90 mg) QD or placebo. Povorcitinib was associated with transcriptomic downregulation of multiple HS and inflammatory signaling markers as well as the reversal of gene expression previously associated with HS lesional and wounded skin. Povorcitinib also demonstrated dose-dependent modulation of several proteins implicated in HS pathophysiology, with changes observed by Week 4. The reversal of HS lesional gene signatures and rapid, dose-dependent protein regulation highlight the potential of JAK1 inhibition to modulate underlying disease pathology in HS.

A Hidradenitis Suppurativa molecular disease signature derived from patient samples by high-throughput RNA sequencing and re-analysis of previously reported transcriptomic data sets.

Hidradenitis suppurativa (HS) is a common, debilitating inflammatory skin disease linked to immune dysregulation and abnormalities in follicular structure and function. Several studies have characterized the transcriptomic profile of affected and unaffected skin in small populations. In this study of 20 patients, RNA from lesional and matching non-lesional skin biopsies in 20 subjects were used to identify an expression-based HS disease signature. This was followed by differential expression and pathway enrichment analyses, as well as jointly reanalyzing our findings with previously published transcriptomic profiles. We establish an RNA-Seq based HS expression disease signature that is mostly consistent with previous reports. Bulk-RNA profiles from 104 subjects in 7 previously reported data sets identified a disease signature of 118 differentially regulated genes compared to three control data sets from non-lesional skin. We confirmed previously reported expression profiles and further characterized dysregulation in complement activation and host response to bacteria in disease pathogenesis. Changes in the transcriptome of lesional skin in this cohort of HS patients is consistent with smaller previously reported populations. The findings further support the significance of immune dysregulation, in particular with regard to bacterial response mechanisms. Joint analysis of this and previously reported cohorts indicate a remarkably consistent expression profile.

Irisin, a novel metabolic biomarker in hidradenitis suppurativa: correlation with clinical responsivity to anti-TNF-α therapy.

BACKGROUND: Suppurative hidradenitis (HS) is a chronic, inflammatory skin disease of the hair follicle unit. Adalimumab (ADA), an anti-tumor necrosis factor (TNF) alpha, is the only FDA-approved biologic available for the management of HS. TNF-α can also affect glucose and lipid metabolism, promoting insulin resistance and obesity by negatively regulating irisin, a new adipomyokine. METHODS: A total of 17 HS patients were enrolled in the study. Blood samples were collected from all patients at baseline and week-16. Plasma irisin levels were detected by ELISA assay. RESULTS: Plasma irisin levels were significantly increased after 16 weeks of ADA therapy in HS patients compared to baseline. Interestingly, plasma irisin levels correlated with clinical response. CONCLUSIONS: The link between skin inflammatory diseases and metabolic disorders has aroused great interest in order to research new biomarkers able to early identify metabolic comorbidities. Among these emerging biomarkers, irisin is one of the most recently discovered. We examined a group of patients affected by moderate-severe HS treated with anti-TNF-α, demonstrating for the first time how a therapy able to block an inflammatory cytokine can also affect the metabolic profile by modifying levels of irisin.

Effects of NCSTN Mutation on Hair Follicle Components in Mice.

BACKGROUND AND OBJECTIVES: Hidradenitis suppurativa (HS)/acne inversa is an intractable skin disease that is characterized by destructive lesions - primarily on the flexural areas. Although its etiology is unknown, genetics is considered to be a factor of its pathology - mutations in γ-secretase genes have been identified in certain familial HS patients, and follicular occlusion is widely accepted as the primary cause of HS. But, no relationship between these mutations and the components of hair follicles has been reported. Thus, we examined changes in these components in mice with a mutation in NCSTN (a γ-secretase gene). METHODS: We generated C57BL/6 mice with an NCSTN mutation and examined their expression of hair cortex cytokeratin and trichohyalin by Western blot and immunohistochemistry, in addition to nicastrin, the product of NCSTN, and NICD compared with wild-type mice. The structure of hair follicles was analyzed by hematoxylin-eosin staining and transmission electron microscopy. RESULTS: In mice with an NCSTN mutation, HS-like skin lesions appeared after age 6 months, the pathological manifestations of which were consistent with the features of human HS. The structure of hair follicles was abnormal in mice with an NCSTN mutation versus wild-type mice, and hair cortex cytokeratin, trichohyalin, nicastrin, and NICD were downregulated in these mice. CONCLUSIONS: This NCSTN mutant mouse model could be an improved model to study early lesion development aspects of human HS pathogenesis and could perhaps be a better alternative for evaluating early-acting and preventive therapeutics for HS experimentally before clinical trials in HS patients. NCSTN mutations disrupt the development of hair follicles, leading to abnormal hair follicle structures, perhaps resulting in the onset of HS.

Cervicofacial hidradenitis suppurativa: A case report and literature review.

Hidradenitis suppurativa (HS) is a chronic inflammatory condition of the apocrine glands primarily affecting the axillae, perineum, and inframammary regions. It is characterized by painful, inflamed cutaneous lesions causing nodules, sinus tracts, and abscesses. Cervicofacial HS is an atypical presentation of HS in the head and neck region and is scarcely reported in the literature. We present a 34-year-old male who developed a large facial swelling overlying the left inferior mandibular border. Management included surgical incision and drainage, antibiotic therapy, followed by infliximab (Remicade). The purpose of this case report was to highlight the presentation, pathophysiology, interdisciplinary approach to treatment and follow-up of patients with cervicofacial HS, and finally, review the cervicofacial HS literature.