Hidradenitis suppurativa (HS) is a chronic inflammatory disease that affects the pilosebaceous units, particularly in large skin folds. The pathophysiology of HS is multifactorial, with evidence suggesting that the microbiome plays a crucial role in perpetuating inflammation. The persistent nature of HS tunnels, coupled with potential dysbiosis in these lesions, may help explain the recurrent episodes of HS, even with systemic treatment. To explore this further, a literature search was conducted on June 20, 2024. A total of eight studies, involving 418 patients, 632 HS lesions, 360 HS tunnels, and 300 controls, were included. The findings from these studies suggested that HS tunnels are characterized by a polymicrobial microbiome, predominantly dominated by anaerobic bacteria such as Porphyromonas , Parvimonas , Fusobacterium , and Prevotella . In contrast, HS tunnels exhibit a notable reduction in saprophytic species like Cutibacterium acnes and Staphylococcus epidermidis , which are commonly found in healthy skin. Disease stage, as classified by the Hurley system, is the most significant factor influencing the microbiome composition of HS tunnels, with advanced lesions showing a greater presence of dysbiotic and pathogenic flora. Interestingly, no significant differences in bacterial colonization were observed based on variables such as sex, age, smoking status, body mass index (BMI), or anatomical location. Larger biofilms with active bacteria were found in tunnels and anaerobic regions of hair follicles. Overall, these results highlight the distinct polymicrobial, predominantly anaerobic bacterial flora of HS tunnels and the significant reduction in commensal bacteria typically found in healthy skin. This specific microbiome may help explain both the pathogenic characteristics and therapeutic challenges associated with HS tunnels.

Background/Objectives: Baricitinib, a selective Janus kinase (JAK) 1 and 2 inhibitor, has recently emerged as a therapeutic option for patients with severe alopecia areata (AA). The aim of this study was to identify clinical and biological predictors of early therapeutic response to baricitinib in patients with AA in real-world clinical practice. Methods: A retrospective cohort study was conducted including patients with AA initiating baricitinib between January 2022 and January 2025. Patients were stratified into early responders and non-early responders. Univariate and multivariate logistic regression analyses were performed to assess factors independently associated with early therapeutic response. Results: A total of 44 patients with AA treated with baricitinib were included, the majority being female (65.9%, 29/44), with a mean age of 37.3 years (SD 16.1). Early responders accounted for 34.1% (15/44) of the cohort. In multivariate analysis, early response to baricitinib was independently associated with a lower baseline Severity of Alopecia Tool (SALT) score, shorter disease duration, and elevated erythrocyte sedimentation rate (ESR) at baseline (p < 0.05). Receiver Operating Characteristic (ROC) curve analyses were performed to determine optimal thresholds for predicting early therapeutic response: ESR ≥ 9 mm/h, baseline SALT score ≤ 60%, and disease duration ≤ 7 years. Conclusions: Baseline stratification using easily obtainable clinical and laboratory parameters may help identify patients most likely to benefit from initiating treatment with baricitinib. Our findings support the existence of a therapeutic window of opportunity in AA, particularly in patients with lower disease burden, shorter disease duration, and elevated ESR values.

Introduction: Hidradenitis suppurativa (HS) is a chronic, progressive, inflammatory skin disease that leads to structural skin alterations, usually assessed using Hurley stages. In Hurley stage I, the earliest phase, structural changes have not yet occurred. However, disease progression varies among patients; some remain indefinitely in this stage, while others advance to more severe forms. The incidence and factors driving progression remain unclear. The aims of this study were to determine the incidence of Hurley II and III cases in a cohort of Hurley I patients and to explore potential factors and interventions associated with structural progression. Methods: A retrospective cohort study was conducted in Hurley I patients to estimate the cumulative incidence and incidence density of Hurley II–III cases during follow-up. Consecutively, within the cohort of Hurley I patients, a nested case-control study was performed to identify factors associated with structural progression. Patients underwent clinical and ultrasound evaluations. Univariate and multivariate analyses were performed. Results: The study included 133 Hurley I patients evaluated consecutively at the HS unit between January 2017 and March 2024. Mean age was 37.54 (12.87) years, with a female-to-male ratio of 84:49. Regarding progression, cumulative incidence was 50 cases (37.6%) (49 to Hurley II; 1 to Hurley III) and incidence density was 23 cases/100 patients-years. After multivariate analysis, the following variables were significantly and independently associated with progression to Hurley stage: higher number of cigarettes/day (p = 0.009), Hurley Ic stage (p = 0.05), and the increase in abscess count from baseline (categorical) (p = 0.0003). A higher number of abscess drainages (p = 0.047) was associated with a lower risk of progression. Conclusion: These findings suggest that clinical features, smoking habits, and treatment-related variables may help identify those patients more likely to progress. Further studies with larger and more representative cohorts are needed to validate these associations.

Background: Conventional systemic therapies, including cyclosporine and methotrexate, have traditionally been used for moderate-to-severe atopic dermatitis (AD). However, their real-world effectiveness and treatment persistence in the era of advanced therapies remain uncertain. Objective: To evaluate the effectiveness, safety, and treatment persistence of cyclosporine and methotrexate in routine clinical practice. Methods: We conducted a retrospective observational cohort study, including patients with moderate-to-severe AD who initiated cyclosporine or methotrexate as first-line systemic therapy. Disease severity and patient-reported outcomes were assessed at treatment initiation and discontinuation. Outcomes after escalation to advanced therapies were also analyzed. Results: A total of 113 patients were included (mean age 33.7 ± 13.4 years; 53.1% female). Conventional systemic therapy was associated with modest clinical improvement, with no significant change in Eczema Area and Severity Index [EASI] (−0.66; P = 0.439) but a reduction in pruritus (Numerical Rating Scale [NRS] itch −1.3; P = 0.001). Median treatment duration was 20.5 weeks, and 96% discontinued therapy, mainly due to lack of efficacy (68.8%). After discontinuation, 76.0% escalated to advanced therapies, which achieved significant improvements in EASI (−11.1; P <0.001) and NRS itch (−3.2; P <0.001). Conclusions: In real-world practice, cyclosporine and methotrexate show limited effectiveness and low persistence, whereas advanced therapies provide substantial clinical benefit.

Background: Hidradenitis suppurativa (HS) is a chronic, relapsing inflammatory skin disease lacking a standardized definition of disease control. While minimal disease activity (MDA) serves as a validated treatment target in psoriasis and atopic dermatitis, no equivalent framework exists for HS, limiting the implementation of treat-to-target strategies. Objective: To propose and validate clinically relevant MDA criteria for HS, integrating objective measures and patient-reported outcomes in a real-world cohort. Methods: Prospective, single-center, and observational study including all patients classified as well-controlled between April 2024 and January 2025. Sociodemographic, clinical, and therapeutic data were collected. In a paired analysis, a subgroup with prior moderate/poor control was compared against their pre-control. Results: Of 547 patients, 170 were classified as well-controlled. At assessment, 85.9% (146/170) had no active lesions, with a mean Localized Activity Index (LAI)—active areas/total affected areas—of 6%, and an International Hidradenitis Suppurativa Severity Score System (IHS4) of 0.38 ± 1.07. Symptomatic burden was minimal, with a mean global visual analog scale (VAS) of 1.24. In 114 paired patients, significant improvements were observed across all domains, including a 92% reduction in LAI and a 97% reduction in IHS4 ( P < .0001). Factor analysis revealed 2 key dimensions—objective inflammation and patient-perceived symptoms—forming the basis for the proposed MDA definition: LAI ≤0.3, IHS4 ≤7, global/pain/suppuration VAS ≤3, and absence of structural progression. These criteria correctly identified 82% of well-controlled patients. Conclusions: This study introduces the first operational definition of MDA in HS, empirically derived and clinically feasible. Adoption of this framework could harmonize disease assessment, guide therapeutic targets, and advance precision management in HS.