Hidradenitis suppurativa (HS) is a chronic, inflammatory, and debilitating disease of hair follicles with 1-4% prevalence and high morbidity. There is a dearth of information on the pathogenesis and immune dysregulation underlying HS; therefore, we carried out a detailed analysis of skin-infiltrating T cells. Cells isolated from skin biopsy samples and blood from HS patients and healthy control subjects were analyzed by 16-parameter flow cytometry to provide detailed profiles of CD4 T-cell subsets. We observed substantial infiltration of inflammatory T cells with a striking T helper (Th) type 17-skewed cytokine profile in HS skin; these cells expressed the Th17 lineage marker CD161 and IL-17, as well as proinflammatory cytokines GM-CSF, IL-22, IFN-γ, and tumor necrosis factor. Regulatory T cells were also enriched in HS lesional skin; however, the ratio of Th17 to regulatory T cells was nonetheless highly dysregulated in favor of Th17 cells. In contrast, lesional skin from anti-tumor necrosis factor-treated HS patients who showed substantial clinical improvement exhibited a significant reduction in the frequency of Th17 cells and normalization of the Th17 to regulatory T cell ratio. These data suggest that inhibition of pathogenic IL-17 via tumor necrosis factor blockade is associated with improvement in immune dysregulation in HS and may provide a rationale for targeting IL-17 in the disease.

BackgroundHidradenitis suppurativa (HS), a chronic inflammatory disease that affects apocrine gland–bearing skin, has a significant impact on patients' quality of life. Estimates of the epidemiologic prevalence of HS are highly variable, and clinical data on disease characteristics and patient burden of disease remain limited.ObjectiveThe primary objective of this study was to determine the number of patients with HS attending dermatology clinics in a hospital setting in Ireland (within a 6‐month time period). Secondary objectives included the assessment of disease characteristics and the collection of patient responses on disease burden and work productivity.MethodsThis was an epidemiologic, non‐interventional, cross‐sectional study across four dermatology clinics in Ireland over a 6‐month time period. The disease prevalence was estimated by calculating the percentage of total patients with a diagnosis of HS (the primary population) across the selected sites. Secondary analyses were performed using the full analysis set, which consisted of eligible adults (≥18 years of age) from the primary population who provided informed consent. Data from these analyses are presented as descriptive summary statistics, with the use of an analysis of covariance for continuous endpoints.ResultsThe prevalence of HS across the four selected sites was estimated at 1.4% (95% CI, 1.24–1.62). One hundred and fifty eligible patients comprised the full analysis set. The majority of participants were white (95.3%), female (70.0%), cigarette smokers (56.0%) and overweight or obese (body mass index ≥25 kg/m2, 81.8%). Most patients for whom data were available presented with Hurley stage II (50.4%), and more than a third of the full analysis set had a relative with HS (34.7%). Questionnaire responses revealed a profound impact on quality of life, including diminished work productivity and various psychological comorbidities.ConclusionThis study offers insight into the clinical features and disease burden of hidradenitis suppurativa in an Irish population.

No abstract

Summary We report eight cases of patients with severe acne who were treated with isotretinoin and developed painful nodules in the axillae and groin, consistent with hidradenitis suppurativa (HS). The pathogenesis of HS is still not completely understood; recent research from a study in 2011 of biopsies from HS lesions showed a reduction or absence of sebaceous glands compared with normal skin in patients with HS, with the report suggesting that this contributes to the pathogenesis of the disease. Interestingly, the main effect of isotretinoin is to decrease the size and action of sebaceous glands, so hypothetically, as isotretinoin acts by reducing the sebaceous glands further it could potentially aggravate HS. Our experience has instilled caution in our prescribing of isotretinoin, and we question patients, particularly those with acne conglobata, about symptoms of HS prior to and during treatment.

No abstract