IL-17 Control of Cutaneous Immune Homeostasis.

IL-17 is widely recognized for its roles in host defense and inflammatory disorders. However, it has become clear that IL-17 is also an essential regulator of barrier tissue physiology. Steady-state microbe sensing at the skin surface induces low-level IL-17 expression that enhances epithelial integrity and resists pathogens without causing overt inflammation. Recent reports describe novel protective roles for IL-17 in wound healing and counteracting physiologic stress; however, chronic amplification of these beneficial responses contributes to skin pathologies as diverse as fibrosis, cancer, and autoinflammation. In this paper, we discuss the context-specific roles of IL-17 in skin health and disease and therapeutic opportunities.

Hidradenitis Suppurativa Patient Referrals to a Canadian Community Dermatology Practice: A Retrospective Chart Review.

INTRODUCTION: Awareness of hidradenitis suppurativa (HS) among non-dermatology healthcare providers is essential to facilitate prompt diagnosis, treatment, and referral to dermatology for further management. OBJECTIVE: The purpose of this study was to analyze recent referrals to a Canadian community dermatology practice and compare the diagnostic concordance rates for HS between dermatologists and non-dermatologists. METHODS: This study was a single-centre, retrospective chart review that was completed at Beacon Dermatology in Calgary, AB. Patients who were referred by a non-dermatologist for suspicion of HS and/or were diagnosed with HS by a dermatologist at Beacon Dermatology for the first time between May 2020 and May 2023 were included. Referral letters and dermatology clinic notes were analyzed to extract patient demographics, suspected pre-referral and post-referral diagnoses, and interim management plans that were initiated by the referring provider. RESULTS: A total of 451 patient charts with suspected and/or confirmed HS were retrieved from the clinic database. The median wait time from referral to the first dermatology appointment was 9.1 weeks. The average duration of HS symptoms was 7.3 years. HS was suspected by the referring provider and confirmed by a dermatologist in 286 cases (63%). Preliminary management was initiated in 60% of mild and 66% of moderate-to-severe cases. DISCUSSION: Given the prolonged time to diagnosis of HS, increasing awareness among healthcare providers is essential. Furthermore, this study highlighted the low implementation rates for evidence-based treatment options in preliminary management plans. Ultimately, this study demonstrates the need for increased interdisciplinary education on HS management in Canada.

Successful treatment of concomitant alopecia universalis and Crohn's disease with upadacitinib: A case report.

Alopecia areata is a non-scarring, autoimmune hair loss disorder that is associated with inflammatory bowel disease. Alopecia areata and inflammatory bowel disease may have a common pathogenic mechanism that involves the Janus kinase/STAT pathway. In addition, there are previous case reports of patients who developed alopecia areata while on biologic therapies for inflammatory bowel disease. JAK1 inhibitors are currently undergoing investigation as potential therapies for Crohn's disease. Upadacitinib, an oral JAK1 inhibitor, has demonstrated efficacy in treating Crohn's disease during phase III clinical trials. In this case report, we present a 23-year-old man with Crohn's disease who previously developed alopecia areata while on adalimumab. He had near-complete resolution of his alopecia universalis after 7 months of treatment with upadacitinib while on concurrent ustekinumab for Crohn's disease, which he had been taking for 16 months prior to starting upadacitinib. Upadacitinib may be a beneficial therapy for treating concomitant alopecia areata and Crohn's disease.

Practical Guidelines for Managing Patients With Hidradenitis Suppurativa: An Update.

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease that is characterized by the formation of comedones, papules, nodules, abscesses and sinus tracts in the axillary, inframammary, groin, and gluteal areas. Up to 3.8% of the Canadian population has HS, though due to a lack of awareness of HS, many patients are initially misdiagnosed and do not receive adequate treatment early on in the disease course. Once a diagnosis of HS is made, developing an effective management plan can be a dilemma for many providers. There is significant variability in response to any given therapy within the HS patient population and many HS patients have other medical comorbidities which must be taken into consideration. The aim of this review is to provide a practical approach for all healthcare providers to diagnose and manage HS and its associated comorbidities. A sample electronic medical record template for HS management was developed by the Canadian Hidradenitis Suppurativa Foundation Executive Board and is intended for use in clinical settings. This will help to increase collaboration between primary healthcare providers, dermatologists, and other medical specialists and ultimately improve the quality of care that HS patients receive.

Maternal low-dose aspartame and stevia consumption with an obesogenic diet alters metabolism, gut microbiota and mesolimbic reward system in rat dams and their offspring.

OBJECTIVE: We examined the impact of maternal low-dose aspartame and stevia consumption on adiposity, glucose tolerance, gut microbiota and mesolimbic pathway in obese dams and their offspring. DESIGN: Following obesity induction, female Sprague-Dawley rats were allocated during pregnancy and lactation to: (1) high fat/sucrose diet (HFS) +water (obese-WTR); (2) HFS +aspartame (obese-APM; 5-7 mg/kg/day); (3) HFS +stevia (obese-STV; 2-3 mg/kg/day). Offspring were weaned onto control diet and water and followed until 18 weeks. Gut microbiota and metabolic outcomes were measured in dams and offspring. Cecal matter from offspring at weaning was used for faecal microbiota transplant (FMT) into germ-free (GF) mice. RESULTS: Maternal APM and STV intake with a HFS diet increased body fat in offspring at weaning and body weight long-term with APM. Maternal APM/HFS consumption impaired glucose tolerance in male offspring at age 8 weeks and both APM and STV altered faecal microbiota in dams and offspring. Maternal obesity/HFS diet affected offspring adiposity and glucose tolerance more so than maternal LCS consumption at age 12 and 18 weeks. APM and STV altered expression of genes in the mesolimbic reward system that may promote consumption of a palatable diet. GF mice receiving an FMT from obese-APM and obese-STV offspring had greater weight gain and body fat and impaired glucose tolerance compared with obese-WTR. CONCLUSION: Maternal low-calorie sweetener consumption alongside HFS may disrupt weight regulation, glucose control and gut microbiota in dams and their offspring most notably in early life despite no direct low-calorie sweetener consumption by offspring.