Hidradenitis suppurativa and atopic dermatitis: A 2-way association

Eosinophils in hidradenitis suppurativa patients exhibit pro-inflammatory traits, implicating a potential pathogenic role in the disease

Hidradenitis suppurativa (HS) is an inflammatory skin disease characterized by painful nodules, abscesses and purulent secretions in intertriginous regions. Intense pruritus frequently accompanies HS lesions, adding further discomfort for patients. While Th17 pathway activation is implicated in HS pathogenesis, disease mechanisms are still not fully understood, and therapeutics are lacking. Previous reports raise a potential role for eosinophils in HS, showing a strong association of eosinophil levels with disease severity. To investigate eosinophils in HS, we recruited patients and matched healthy controls and then performed flow-cytometry studies, eosinophil stimulation assays, and lesional skin staining for eosinophils. We found that HS patients reported similar levels of pain and itch. Compared to matched controls, HS blood exhibited decreased mature eosinophils and increased numbers of immature eosinophils, coupled with a significant increase in dermal eosinophilic infiltrates. Additionally, IL-17RA+ eosinophils were highly and significantly correlated with multiple HS-related clinical scores. In both stimulated and unstimulated conditions, HS eosinophils showed an inflammatory phenotype versus controls, including an increase in costimulatory T- and B-cell markers (e.g. CD5 and CD40) following all stimulations (TNFα/IL-17A/IL-17F). These findings highlight the significance of pruritus in HS and suggest a higher turnover of eosinophils in HS blood, potentially due to the consumption of eosinophils in skin lesions. Our data delineate the features and functions of eosinophils in HS and suggest that eosinophils participate in disease pathogenesis, advancing Th17-related inflammation. Further studies are needed to investigate eosinophils' response to current HS treatments and their potential as a therapeutic target in the disease.

A history of asthma is associated with susceptibility to hidradenitis suppurativa: a population-based longitudinal study

The association of hidradenitis suppurativa (HS) and asthma remains to be investigated. To assess the bidirectional association between HS and asthma. A population-based study was conducted to compare HS patients (n = 6779) with age-, sex-, and ethnicity-matched control subjects (n = 33,259) with regard to the incidence of new onset and the prevalence of preexisting asthma. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were calculated. The prevalence of preexisting asthma was higher in patients with HS relative to controls (9.6% vs. 6.9%, respectively; P < 0.001). The odds of HS were 1.4-fold greater in patients with a history of asthma (fully adjusted OR 1.41; 95% CI 1.27-1.55; P < 0.001). The incidence rate of new-onset asthma was estimated at 9.0 (95% CI 6.3-12.7) and 6.2 (95% CI 5.1-7.5) cases per 10,000 person-years among patients with HS and controls, respectively. The risk of asthma was not statistically different in patients with HS and controls (fully adjusted HR 1.53; 95% CI 0.98-2.38; P = 0.062). Relative to other patients with HS, those with HS and comorbid asthma were younger at the onset of HS (30.7 [14.7] vs. 33.3 [15.1], respectively; P < 0.001) and had a comparable risk of all-cause mortality (adjusted HR 0.86; 95% CI 0.44-1.68; P = 0.660). A history of asthma confers susceptibility to subsequent development of HS. This observation is of importance for clinicians managing both patients with HS and asthma. Further research is warranted to elucidate the pathomechanism underlying this finding.

Epidemiology and comorbidity of hidradenitis suppurativa in Korea for 17 years: A nationwide population-based cohort study

Hidradenitis suppurativa (HS) is associated with various metabolic and autoimmune diseases. The epidemiology has been analyzed in various studies worldwide. However, epidemiological data on HS for Asian populations are limited. This study aimed to analyze the change in the prevalence and incidence of HS over 17 years in South Korea using the Korean National Health Insurance Service (NHIS) database. This study also evaluated the comorbidities in patients with HS. Population-based data from the NHIS database of Korea were obtained between January 2003 and December 2019. Odds ratios were estimated to determine the association between comorbidities and HS during the study period. Hazard ratios for the risk of incident comorbidities in patients with HS were obtained using the multivariable Cox proportional hazard analysis. This study included 45 511 patients with HS and 910 220 controls matched for age, sex, insurance type, and income level. The incidence rate of HS per 1 000 000 person-years in Korea increased from 11.69 in 2003 to 78.78 in 2019. The annual prevalence per 1 000 000 people also increased from 34.68 in 2003 to 140.10 in 2019, showing a similar trend. Many comorbidities, including atopic, metabolic and end-organ, autoimmune/inflammatory, and psychiatric diseases were associated with HS at baseline. In many diseases, the risk of incident comorbidities in patients with HS was higher than that in controls. The incidence and prevalence of HS in Korea have increased over the past 17 years. Various comorbidities, including allergic diseases, hypertension, diabetes mellitus, dyslipidemia, myocardial infarction, chronic hepatitis and cirrhosis, chronic kidney disease, inflammatory bowel diseases, rheumatoid arthritis, vitamin D deficiency, and psychiatric diseases, were associated with HS. Physicians need to keep in mind and closely monitor these comorbidities in patients with HS.

Comorbid diseases of hidradenitis suppurativa: a 15-year population-based study in Olmsted County, Minnesota, USA

BACKGROUND

Like other chronic, inflammatory skin disorders, hidradenitis suppurativa (HS) is increasingly recognized to be associated with various medical disorders.

OBJECTIVE

Using the Rochester Epidemiology Project (REP), we sought to conduct the first American population-based study examining the association between HS and various comorbid conditions.

METHODS

From the REP database, we identified patients diagnosed with HS from 2003 through 2018 who were residents of Olmsted County, Minnesota, USA, along with age- and gender-matched controls. The frequency of a wide variety of comorbid conditions was compared between the groups.

RESULTS

A total of 1160 patients with HS were identified during the study period. Compared with age- and gender-matched controls, patients with HS had a significantly higher frequency of several medical conditions, including depression, anxiety, hyperlipidemia, acne conglobata, dissecting cellulitis, pilonidal cysts, polycystic ovary syndrome, diabetes, chronic kidney disease, psoriasis, atopic dermatitis, obesity, and disordered substance use, among others.

LIMITATIONS

Our study was limited by its retrospective design.

CONCLUSIONS

Providers caring for patients with HS should consider these results, along with those of similar studies, and obtain a thorough history, comprehensive physical examination, and, potentially, laboratory testing and referral to other specialists.

Ablation of Basic Leucine Zipper Transcription Factor ATF-Like Potentiates Estradiol to Induce Atopic Dermatitis

Background

Atopic dermatitis (AD) is an inflammatory and immune skin disorder. Basic leucine zipper transcription factor ATF-like (BATF) plays a key role in regulating the differentiation and functions of lymphocytes. However, the mechanism underlying the transcriptional regulation of BATF on AD is still not well understood.

Methods

BATF knockout (BATF-/-) and C57BL/6(B6) mice were used for the development of spontaneous dermatitis. 17β-Estradiol was injected intraperitoneally to induce AD. The lesioned tail skin of the mice was stained with hematoxylin and eosin to analyze the pathological characteristics. Impaired skin barrier function was assessed by measuring the transepidermal water loss (TEWL). The skin epithelial barrier indicators and cytokine mRNA levels were quantified by real-time quantitative PCR. The total serum immunoglobulin E (IgE) levels were measured by enzyme-linked immunosorbent assay (ELISA). T lymphocytes were analyzed using flow cytometry.

Results

Ablation of BATF led to the spontaneous development of AD only in female mice and not in male mice. BATF deletion led to elevated serum levels of IgE and increased infiltration of eosinophils, neutrophils, and lymphocytes and promoted cytokine production including IL-4, IL-22, IL-1β, IFN-γ, and TNF-α in the lesioned tail skin of the mice. The mRNA expression levels of filaggrin and loricrin significantly decreased, while S100A8 and S100A9 increased in female BATF-/- mice. BATF-deficient female mice were found to increase proliferation and IL-5 production by skin-infiltrating CD4+ T cells which implies Th2 activation. Moreover, AD was successfully induced only in the estradiol-treated BATF-deficient male mice and not in WT male mice. Estradiol enhanced the allergic and immunological responses to dermatitis primarily by triggering Th2-type immune responses via enhanced serum IgE and inflammatory cytokine levels in the male BATF-/- mice.

Conclusion

The study concluded that BATF potentiates estradiol to induce mouse atopic dermatitis via potentiating inflammatory cytokine releases and Th2-type immune responses and may have important clinical implications for patients with AD.

Development and characterisation of an irradiation device for biomedical studies covering the solar spectrum with individual regulated spectral bands

To understand the importance of terrestrial solar exposure on human skin, not only individual spectral components need to be considered in biomedical studies, but also the relevance of the combined action profile of the complete solar spectrum (cSS) must be established. We therefore developed a novel irradiation device that combines the emission of four individual lamps (UVB, UVA, VIS and nIR) to achieve exposure from 280 to 1400 nm with individual controllable lamps. The integrated irradiance of each spectral band is similar to the solar spectrum. The lamps can be utilised individually or in any desired combination. Here we present the design, realisation, and validation of this irradiation device as well as biological results on cellular metabolism (MTT assay), cell cycle alterations, and clonogenic growth in HaCaT cells after exposures to the individual spectral bands as well as their simultaneous combinations. Thereby, we demonstrate that UVB combined with UVA is the main determinant for the metabolic activity within cSS. Also, UVB-dependent effects dominate cell cycle regulation in cSS, whilst UVA and nIR have little influence. Lastly, also clonogenic growth is dominated by the UVB action profile in cSS, despite nIR showing modulatory activity when applied in combination with UVB. Together, this highlights the regulatory influence of the different spectral bands on the three biological endpoints and demonstrates their modulation when being part of the complete solar spectrum.

Insights into hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, debilitating, inflammatory skin disorder with a prevalence of around 1% and a profound impact on patients' quality of life. Characteristic lesions such as inflammatory nodules, abscesses, and sinus tracts develop in the axillae, inguinal, and gluteal areas, typically during or after puberty. A complex interplay of genetic predisposition, hormonal factors, obesity, and smoking contributes to development and maintenance of the disease. HS is considered to arise from an intrinsic defect within the hair follicle, leading to follicular plugging, cyst formation, and subsequent rupture that in turn induce an acute inflammatory response characterized by elevated levels of IL-1β, IL-17, and TNF. Over time, acute lesions transition into chronic disease, with active draining sinus tracts accompanied by extensive fibrosis. HS is associated with other immune-mediated inflammatory diseases, metabolic and cardiovascular disorders, and psychiatric comorbidities. Treatment of HS often requires a combination of antibiotic or immunosuppressing therapies and surgical intervention. Nonetheless, the currently available treatments are not universally effective, and many drugs, which are often repurposed from other inflammatory diseases, are under investigation. Studies into the early stages of HS may yield treatments to prevent disease progression; yet, they are hampered by a lack of appropriate in vitro and animal models.

Physical and psychosocial comorbidities of pediatric hidradenitis suppurativa: A retrospective analysis

BACKGROUND/OBJECTIVES

Hidradenitis suppurativa (HS) is understudied in the pediatric population. Adult HS patients are known to have a high comorbidity burden. We aimed to describe physical and psychosocial comorbidities in a cohort of pediatric HS patients.

METHODS

A retrospective chart review of pediatric HS patients at a single academic institution was conducted. Data on patient demographics, disease characteristics, and physical and psychosocial comorbidities in pediatric patients with HS were collected and analyzed.

RESULTS

Seventy-three pediatric patients were included in this study, 81% female. Mean (SD) age of HS disease onset was 12.6 (2.9) years. Comorbid conditions were reported in 68 of 73 (93%) patients. Significantly increased rates of several comorbidities were seen in our cohort as compared to the general US pediatric population. Metabolic and endocrine abnormalities were prevalent, with 52% (22/42) patients with obesity and 10% (6/59) with polycystic ovary syndrome. The most common cutaneous comorbidity was acne vulgaris, seen in 37% (27/73) of patients. Over one quarter (21/73, 29%) of patients had either an anxiety or depression disorder. Almost one-fifth (14/73, 19%) of our cohort had a diagnosis of asthma and other reactive airway diseases. Only one-third (24/73, 33%) of patients had documentation regarding impact of HS on their daily life. Overall, comorbidities largely did not significantly differ based on race, gender, or disease severity.

CONCLUSIONS

Pediatric patients with HS face a high-comorbidity burden, especially with psychiatric conditions. Early identification, including routine mental health screening, and management of comorbidities is warranted in the pediatric HS population.

Red Dot Basal Cell Carcinoma: Literature Review of a Unique Clinical Subtype of Basal Cell Carcinoma

Red dot basal cell carcinoma is a distinctive clinical subtype of basal cell carcinoma. It has been reported in eight individuals with a male to female ratio of 1:1; and the patients' ages ranged from 50 to 74 years. All patients had prior history of actinic keratoses and basal cell carcinoma. In addition, some patients also had prior squamous cell carcinoma, malignant melanoma, and/or dysplastic nevus. The tumor was usually of recent onset, asymptomatic, and on sun-exposed skin. It was most commonly located on the nose (five patients); other sites were the upper lip, the mid back, or thigh-each in one patient. The red dot basal cell carcinoma was solitary and small-usually 4 mm or less in diameter. It typically presented as a red macule or papule; however, it sometimes appeared as a flesh-colored or pink to light-red papule with a bright-red central area. Microscopic features showed basaloid tumor cells (arranged as either nodular aggregates or superficial buds or both). In the central portion of the lesion, there was a proliferation of erythrocyte-containing vascular spaces between the epidermis and the neoplasm. The basal cell carcinoma pathology subtype was either nodular and superficial (three patients), nodular (two patients), or superficial (one patient). The clinical differential diagnosis of red dot basal cell carcinoma included not only benign vascular lesions (such as hemangioma and telangiectasia) but also inflammatory conditions and adnexal tumors. Other basaloid cell neoplasms were in the pathologic differential diagnosis. The pathogenesis of red dot basal cell carcinoma is similar to that of other basal cell carcinoma clinical subtypes. Mohs surgery is the treatment of choice for red dot basal cell carcinomas. Red dot basal cell carcinoma has two categories of biologic behavior based on the ratio of the postoperative wound size as compared with the size of the preoperative tumor: nonaggressive (for which the ratio was 5:1 or less for three patients) and aggressive (for which the ratio was greater than 12:1 for three patients). There was no recurrence of the red dot basal cell carcinoma after treatment. In conclusion, the incidence of red dot basal cell carcinoma-a unique morphologic variant of basal cell carcinoma-may be higher than suggested by the number of reported patients with this basal cell carcinoma subtype.