Tree-Based Machine Learning to Identify Predictors of Psoriasis Incidence at the Neighborhood Level: A Populational Study from Quebec, Canada.

BACKGROUND: Psoriasis is a major global health burden affecting ~ 60 million people worldwide. Existing studies on psoriasis focused on individual-level health behaviors (e.g. diet, alcohol consumption, smoking, exercise) and characteristics as drivers of psoriasis risk. However, it is increasingly recognized that health behavior arises in the context of larger social, cultural, economic and environmental determinants of health. We aimed to identify the top risk factors that significantly impact the incidence of psoriasis at the neighborhood level using populational data from the province of Quebec (Canada) and advanced tree-based machine learning (ML) techniques. METHODS: Adult psoriasis patients were identified using International Classification of Disease (ICD)-9/10 codes from Quebec (Canada) populational databases for years 1997-2015. Data on environmental and socioeconomic factors 1 year prior to psoriasis onset were obtained from the Canadian Urban Environment Health Consortium (CANUE) and Statistics Canada (StatCan) and were input as predictors into the gradient boosting ML. Model performance was evaluated using the area under the curve (AUC). Parsimonious models and partial dependence plots were determined to assess directionality of the relationship. RESULTS: The incidence of psoriasis varied geographically from 1.6 to 325.6/100,000 person-years in Quebec. The parsimonious model (top 9 predictors) had an AUC of 0.77 to predict high psoriasis incidence. Amongst top predictors, ultraviolet (UV) radiation, maximum daily temperature, proportion of females, soil moisture, urbanization, and distance to expressways had a negative association with psoriasis incidence. Nighttime light brightness had a positive association, whereas social and material deprivation indices suggested a higher psoriasis incidence in the middle socioeconomic class neighborhoods. CONCLUSION: This is the first study to highlight highly variable psoriasis incidence rates on a jurisdictional level and suggests that living environment, notably climate, vegetation, urbanization and neighborhood socioeconomic characteristics may have an association with psoriasis incidence.

Baseline Characteristics of Canadian Patients in the Psoriasis Longitudinal Assessment and Registry (PSOLAR).

BACKGROUND: The Psoriasis Longitudinal Assessment and Registry (PSOLAR) is a global, prospective, longitudinal, disease-based registry. It serves as a post-marketing safety commitment with a focus on patients with moderate to severe plaque psoriasis who are candidates for systemic therapy. OBJECTIVES: To describe the baseline disease demographics and clinical characteristics of a Canadian subgroup of participants enrolled in PSOLAR. METHODS: Baseline demographic/disease characteristics, medical histories, and previous psoriasis treatments for Canadian patients in PSOLAR were summarized using descriptive statistics. RESULTS: There were 1896 patients analyzed in the Canadian subgroup at 37 clinical sites, accounting for 15.7% of the global PSOLAR population. Baseline disease and clinical characteristics were as expected for a moderate to severe psoriasis population and were generally similar to the global PSOLAR population. Two distinctions were noted in the Canadian subgroup versus those enrolled globally: a higher proportion of patients were overweight/obese (84.7% vs. 80.4%) and male (61.4% vs. 54.7%). In addition, the Canadian subgroup had numerically higher historical peak disease activity (PGA score 3.35 vs. 3.1) and longer disease duration (22.3 years vs. 17.5 years). Canadian PSOLAR patients reported a variety of comorbidities, including psoriatic arthritis (31.5%), hypertension (34.6%), hyperlipidemia (24.3%), mental illness (24.1%), and inflammatory bowel disease (1.6%). CONCLUSION: The Canadian subgroup of PSOLAR patients was generally similar to those enrolled globally with respect to baseline disease demographics and clinical characteristics. Multiple comorbidities are noted in the Canadian subgroup, underscoring the need for a holistic approach to the treatment of psoriatic patients.

Assessing Skin Cancer Risk Factors, Sun Safety Behaviors and Melanoma Concern in Atlantic Canada: A Comprehensive Survey Study.

BACKGROUND: The incidence of cutaneous melanoma (CM) is increasing at an alarming rate in Canada and elsewhere around the world. Significant regional differences in CM incidence have been identified in Atlantic provinces. The goal of this study is to compare ultraviolet exposure, sun protective behaviours, level of worry and baseline CM knowledge in provinces with a high versus low incidence of CM as well, as between various demographic groups. METHODS: A cross-sectional survey study was conducted in Atlantic provinces between July 2020 and August 2022. All participants aged ≥ 16 years with a completed survey were eligible. Survey responses were summarized using frequency counts, percentages, and means. Two-sided Z-tests for equality of proportions and logistic regression models were used to compare the survey results between geographic and demographic groups. RESULTS: In total, 7861 participants were included (28.0% men; mean age 61.3 years; response rate 28%). Our results (gender- and age-adjusted odds ratio, 95% confidence interval) show that high-incidence provinces for CM (Prince Edward Island and Nova Scotia) had significantly more sunburns (OR 2.00, 1.72-2.31), total sun exposure (OR 2.05, 1.68-2.50), recreational sun exposure (OR 1.95, 1.61-2.35) and tans (OR 1.77, 1.53-2.05) than individuals in low-incidence provinces (Newfoundland and Labrador). However, individuals in high-incidence provinces displayed more protective behaviors: there were less tanning bed users (OR 0.82, 0.71-0.95), they checked their skin more frequently for new moles (OR 1.26, 1.06-1.51) and practiced more sun protection overall. Additional analyses are presented based on education, income, sexual orientation and gender. DISCUSSION: These findings suggest that future efforts aimed at reducing the CM burden in Atlantic Canada should be tailored for target geographic and/or demographic groups. LIMITATIONS: the study participants are not representative of the population in Atlantic Canada due to recruitment strategies.

A partitioned 88-loci psoriasis genetic risk score reveals HLA and non-HLA contributions to clinical phenotypes in a Newfoundland psoriasis cohort.

Psoriasis is an immune-mediated inflammatory skin disease typically characterized by erythematous and scaly plaques. It affects 3% of the Newfoundland population while only affecting 1.7% of the general Canadian population. Recent genome-wide association studies (GWAS) in psoriasis have identified more than 63 genetic susceptibility loci that individually have modest effects. Prior studies have shown that a genetic risk score (GRS) combining multiple loci can improve psoriasis disease prediction. However, these prior GRS studies have not fully explored the association of GRS with patient clinical characteristics. In this study, we calculated three types of GRS: one using all known GWAS SNPs (GRS-ALL), one using a subset of SNPs from the HLA region (GRS-HLA), and the last using non-HLA SNPs (GRS-noHLA). We examined the relationship between these GRS and a number of psoriasis features within a well characterized Newfoundland psoriasis cohort. We found that both GRS-ALL and GRS-HLA were significantly associated with early age of psoriasis onset, psoriasis severity, first presentation of psoriasis at the elbow or knee, and the total number of body locations affected, while only GRS-ALL was associated with a positive family history of psoriasis. GRS-noHLA was uniquely associated with genital psoriasis. These findings clarify the relationship of the HLA and non-HLA components of GRS with important clinical features of psoriasis.

Update on Hormonal Therapy in Hidradenitis Suppurativa.

Hidradenitis suppurativa (HS), a chronic inflammatory disorder of the apocrine-bearing skin, presents with deep seated inflamed nodules, abscesses, draining sinus tracts, and scarring with a profound impact on quality of life. In this review of Pubmed, EMBASE, and Cochrane Central databases, we focus on the role of hormonal therapies in the treatment of HS, including finasteride, cyproterone acetate, spironolactone, oral contraceptive pills, and metformin. A detailed search was conducted on these databases using key words like ‘hidradenitis suppurativa’, ‘acne inversa’, ‘antiandrogens’, and ‘hormonal therapy’. J Drugs Dermatol. 2023;22(4): doi:10.36849/JDD.6235 Citation: Karagaiah P, Daveluy S, Ortega Loayza A, et al. Update on hormonal therapy in hidradenitis suppurativa. J Drugs Dermatol. 2023;22(4):369-374. doi:10.36849/JDD.6235.

External Validation of the IHS4-55 in a European Antibiotic-Treated Hidradenitis Suppurativa Cohort.

BACKGROUND: Previously, a new dichotomous outcome was developed, calculated as 55% reduction in the International Hidradenitis Suppurativa 4 (IHS4-55) score. It was validated in datasets of adalimumab and placebo-treated HS patients. External validation is an important aspect of clinical outcomes. OBJECTIVES: We aimed to externally validate the novel dichotomous IHS4-55 in a non-biologic treated dataset of HS patients. METHODS: Data from a previously published European-wide prospective clinical study of antibiotic treatment of HS patients were used to assess the association of IHS4-55 achievement with individual reduction in inflammatory nodules, abscesses, and draining tunnels. Moreover, the associations between IHS4-55 positivity and achievement of the minimal clinically important differences (MCIDs) for Dermatology Life Quality Index (DLQI), Numerical Rating Scale (NRS) Pain, and NRS Pruritus were analyzed. RESULTS: Data were obtained from 283 individual patients, of which 36.4% (103/283) were treated with clindamycin and rifampicin and 63.6% (180/283) with tetracyclines for 12 weeks. Achievers of the IHS4-55 demonstrated a significant reduction the counts of inflammatory nodules, abscesses, and draining tunnels (all p < 0.001). Additionally, IHS4-55 achievers had an odds ratio for achieving the MCID of DLQI, NRS Pain, and NRS Pruritus of 2.16 (95% CI 1.28-3.65, p < 0.01), 1.79 (95% CI 1.10-2.91, p < 0.05), and 1.95 (95% CI 1.18-3.22, p < 0.01), respectively. CONCLUSIONS: This study shows the external validity of the novel IHS4-55 by demonstrating a significant association between IHS4-55 achievement and a reduction in inflammatory lesion counts as well as achievement of MCIDs for DLQI, NRS Pain, and NRS Pruritus in an antibiotic-treated cohort. These findings support the use of the IHS4-55 as a novel primary outcome measure in clinical trials.

Treatment Persistence of Ixekizumab in Adults with Moderate-to-Severe Plaque Psoriasis Participating in the Canadian Patient Support Program.

INTRODUCTION: Patients with psoriasis (PsO) should adhere to and be persistent with treatment to maintain disease control. Patient support programs (PSPs) are useful to support patients with disease management. We aimed to understand the real-world patient profile and persistence of ixekizumab-initiating Canadian patients with moderate-to-severe PsO using PSP data. METHODS: This retrospective observational study was conducted utilizing a Canadian PSP database (May 2016 to March 2020). Inclusion criteria were: age ≥ 18 years with moderate-to-severe PsO, initiated ixekizumab, enrolled in the PSP for ≥ 6 months, and provided informed consent. Psoriasis Area Severity Index (PASI), body surface area (BSA) involvement, and Dermatology Life Quality Index (DLQI) were collected at PSP entry. Adherence [using the proportion of days covered (PDC)] and persistence (using Kaplan-Meier curves) were assessed after 1-year and 2-year follow-ups. Differences in persistence between biologic-naïve and biologic-experienced patients were compared using Cox proportional hazards model after adjusting baseline parameters. RESULTS: In total, 1891 ixekizumab-treated moderate-to-severe patients with PsO were included. The mean [standard deviation (SD)] age was 52.3 (13.3) years; 51.1% of patients were 45-65 years old and 61.4% were male. At baseline, the mean (SD) PASI score was 14.3 (8.1), the DLQI score was 16.5 (7.7), and BSA % was 17.4 (15.1). PsO lesions were commonly located on the hands (33.4%), face (28.6%), and feet (23.8%). Ixekizumab-treated patients were highly adherent [PDC ≥ 80%: 1-year (92.0%), 2-year (87.7%)] and persistent [1-year (90.4%), 2-year (85.6%)]. Biologic-naïve patients were more adherent (1-year, 94.6% versus 87.3%; 2-year, 90.3% versus 83.5%) than biologic-experienced patients. Significantly higher persistence in biologic-naïve versus biologic-experienced patients for 1-year (p < 0.01) and 2-year (p = 0.010) follow-up periods was observed after adjusting for baseline parameters. CONCLUSION: Patients with moderate-to-severe PsO overwhelmingly remained on ixekizumab treatment for more than 2 years while participating in a PSP.

Development and validation of IHS4-55, an IHS4 dichotomous outcome to assess treatment effect for hidradenitis suppurativa.

BACKGROUND: Validated, inclusive and easy-to-use outcomes for hidradenitis suppurativa are essential both in the clinical trial setting and clinical practice. The continuous IHS4 is a validated tool that dynamically assesses nodules/abscesses/draining tunnels and classifies disease severity as mild/moderate/severe. However, dichotomous outcomes are often required for clinical trials reporting. OBJECTIVE: To develop and validate a dichotomous outcome based on IHS4 that can be used in clinical trial settings and day-to-day clinical practice. METHODS: De-identified data from the PIONEER-I and -II studies were accessed through Vivli. Potential IHS4 thresholds were analysed using baseline to Week 12 data from adalimumab- and placebo-treated hidradenitis suppurativa patients in the PIONEER-I trial. The final threshold was chosen based on its ability to discriminate between patients treated with adalimumab or placebo and its association with reduction in inflammatory lesions. The final threshold was validated using data from baseline to Week 12 from adalimumab- and placebo-treated hidradenitis suppurativa patients in both the PIONEER-II and the combined PIONEER-I and -II studies. RESULTS: The best performing cut-off for the IHS4 was a 55% reduction of the IHS4 score (IHS4-55). Patients who achieved the IHS4-55 had an odd's ratio of 2.00 [95%-CI 1.26-3.18, p = 0.003], 2.79 (95%-CI 1.76-4.43, p < 0.001) and 2.16 (95%-CI 1.43-3.29, p < 0.001) for being treated with adalimumab rather than placebo in PIONEER-I, PIONEER-II and the combined dataset, respectively. Additionally, the achievement of the IHS4-55 was associated with a significant reduction in inflammatory nodules, abscesses and draining tunnels in all analysed datasets. CONCLUSIONS: IHS4-55, a novel dichotomous IHS4 version, based on a 55% reduction of the total score was developed. The IHS4-55 performs similarly to the HiSCR in discriminating between adalimumab- and placebo-treated hidradenitis suppurativa patients and shows significant associations with reductions in lesion counts. Moreover, the IHS4-55 addresses some of the HiSCR drawbacks by dynamically including draining tunnels in a validated manner. By allowing the analysis of hidradenitis suppurativa patients with an abscess and nodule count below 3 but many draining tunnels, this outcome measure will improve inclusivity in clinical trials.

Efficacy of guselkumab, a selective IL-23 inhibitor, in Preventing Arthritis in a Multicentre Psoriasis At-Risk cohort (PAMPA): protocol of a randomised, double-blind, placebo controlled multicentre trial.

INTRODUCTION: Psoriatic arthritis (PsA) is a complex, immune-mediated disease associated with skin psoriasis that, if left untreated, can lead to joint destruction. Up to 30% of patients with psoriasis progress to PsA. In most cases, psoriasis precedes synovio-entheseal inflammation by an average of 5-7 years, providing a unique opportunity for early and potentially preventive intervention in a susceptible and identifiable population. Guselkumab is an effective IL-23p19 inhibitor Food and Drug Administration (FDA-approved for treatment of moderate-to-severe psoriasis and PsA. The Preventing Arthritis in a Multicentre Psoriasis At-Risk cohort (PAMPA) study aims to evaluate the efficacy of guselkumab in preventing PsA and decreasing musculoskeletal power Doppler ultrasound (PDUS) abnormalities in a population of patients with psoriasis who are at-increased risk for PsA progression. METHODS AND ANALYSIS: The PAMPA study is a multicentre, randomised, double-blind, placebo-controlled, interventional, preventive trial comparing PDUS involvement and conversion to PsA in patients with psoriasis at-increased risk for progression treated with guselkumab compared with non-biological standard of care. The study includes a screening period, a double-blind treatment period (24 weeks) and an open-label follow-up period (72 weeks). At baseline, 200 subjects will be randomised (1:1) to receive either guselkumab 100 mg (arm 1) or placebo switching to guselkumab 100 mg starting at week 24 (arm 2). Arm 3 will follow 150 at-risk psoriasis patients who decline biological therapy and randomisation. Changes from baseline in the PDUS score at week 24 and the difference in proportion of patients transitioning to PsA at 96 weeks will be examined as the coprimary endpoints. ETHICS AND DISSEMINATION: Ethics approval for this study was granted by the coordinating centre's (NYU School of Medicine) Institutional Review Board (IRB). Each participating site received approval through their own IRBs. The findings will be shared in peer-reviewed articles and scientific conference presentations. TRIAL REGISTRATION NUMBER: NCT05004727.

Extracorporeal Photopheresis and Its Use in Clinical Dermatology in Canada

Extracorporeal photopheresis (ECP) is an immunomodulatory therapy that has been used for over 35 years to treat numerous conditions. ECP was initially approved by the US FDA in 1988 for the treatment of Sézary syndrome, a leukemic form of cutaneous T-cell lymphoma (CTCL). Although CTCL remains the only FDA-approved indication, ECP has since been used off-label for numerous other conditions, including graft-versus-host disease (GvHD), systemic sclerosis, autoimmune bullous dermatoses, Crohn's disease, and prevention of solid organ transplant rejection. In Canada, ECP is mainly used to treat CTCL, acute and chronic GvHD, and in some instances systemic sclerosis. Herein, we review the current concepts regarding ECP mechanism of action, treatment considerations and protocols, and efficacy.

International Dermatology Outcome Measures (IDEOM): Report from the 2021 Annual Meeting.

BACKGROUND: International Dermatology Outcome Measures (IDEOM) is a non-profit organization founded in 2013. It is composed of researchers and stakeholders who work to develop evidenced-based outcome measures to enhance research and treatment recommendations of dermatologic diseases. SUMMARY: The 2021 IDEOM Virtual Annual Meeting occurred from November 19-20, 2021. Contributions were made by leaders and stakeholders from the psoriasis, psoriatic arthritis, pediatric hidradenitis suppurativa, acne, vitiligo, actinic keratosis, alopecia areata, itch, and cutaneous lymphoma workgroups. The psoriasis, psoriatic arthritis, and actinic keratosis workgroups provided an overview of their respective instruments for treatment satisfaction and symptom measurement. The inaugural meetings of the itch, alopecia areata, and cutaneous lymphoma workgroups identified unmet needs of their respective diseases and future goals. The acne, vitiligo, and pediatric hidradenitis suppurativa workgroups discussed concerns of quality of life, instruments for symptom measurement, and screening tools. Additionally, a representative from the US Food and Drug Administration was in attendance and presented an update on topical drugs and generics. This report provides a summary of workgroup updates from the past year and future directions established during the meeting. KEY MESSAGES: This report summarizes progress made by each IDEOM workgroup at the 2021 IDEOM Virtual Annual Meeting. J Drugs Dermatol. 2022;21(8):867-874. doi:10.36849/JDD.6974.

Real World Studies of Psoriasis and Mental Illness in Newfoundland and Labrador.

BACKGROUND: Psoriasis is a chronic, immune-mediated inflammatory disease with an implied connection to psychiatric disorders. OBJECTIVE: This study aims to illustrate an association between psoriasis and psychiatric disorders using real world data gathered from the Newfoundland and Labrador population. METHODS: Data on 15,100 patients with psoriasis and 75,500 controls (1:5) was collected from the Newfoundland and Labrador Centre for Health Information's Electronic Health Records. The cases and controls were matched for age, sex, and geography. Indicators for psychiatric disorders include diagnosis of mental illnesses from physician's visits and hospitalization records (all coded for mental health using ICD-9 and ICD-10 codes). RESULTS: 9,991 (66.2%) cases were identified to have at least one visit with a diagnostic code for mental illness compared to 42,276 (56.0%), P < .0001 in the control group. The percentage of people coded for anxiety was 36.50% compared to 28.95%, P < .0001; depression was 37.04% compared to 30.19%, P < .0001; and adjustment disorder was 6.89% versus 5.48%, P < .0001, among those with and without psoriasis, respectively. The greatest risk for anxiety [OR 1.4 (1.20, 1.67)] and depression [OR 1.65 (1.36, 2.00)] among psoriasis patients was between the 0 to 20 age group. Women with psoriasis are more likely to have anxiety [OR 1.08 (1.03, 1.13)], depression [OR 1.04 (1.01, 1.09)] and adjustment disorder [OR 1.07 (0.98, 1.17)] compared to female controls. CONCLUSION: Our result shows that patients with psoriasis have an increased prevalence of mental illness. Using real world data to carry out further investigations will better elucidate this association and provide an increased understanding of the association between psoriasis and mental disorders.

Real-World Moderate-to-Severe Hidradenitis Suppurativa: Decrease in Disease Burden With Adalimumab.

BACKGROUND: Real-world knowledge of the burden of hidradenitis suppurativa (HS) on patients remains limited. OBJECTIVES: To measure the impact of adalimumab on moderate-to-severe HS patients' health-related quality of life (HRQoL) and work productivity. METHODS: In 23 Canadian centres, 138 adults with moderate-to-severe HS requiring a change in ongoing therapy were treated with adalimumab for up to 52 weeks as per the physician's practice. Patient-reported outcome measures (PROMs) were obtained at baseline, weeks 24 and 52 to measure overall HRQoL, HS severity, levels of anxiety and depression, impact and symptoms of HS, work productivity and activity impairment. A post-hoc analysis further explored the PROMs by abscess and inflammatory nodule (AN) count at baseline (≤5, low; 6-10, medium; ≥11, high). RESULTS: From baseline to weeks 24 and 52, all PRO overall scores improved significantly (P ≤ .0023). The number of patients reporting "good disease control" and "complete disease control" increased from 9.7% to 66.4% over 52 weeks. The score in Health Utility Index Mark 3 (HUI3) pain attribute meaningfully decreased over 52 weeks (mean difference ≥.05). The HS symptoms skin "tenderness" and "itchiness" improved the most. Work productivity loss and activity impairment improved by approximately 20% over 52 weeks. Disease burden improved more in 24 week responders with low and medium AN counts at baseline than in those with high AN count or in 24 week nonresponders. CONCLUSION: At week 24 and maintained at week 52 in a real-world setting, adalimumab meaningfully improved HRQoL, work productivity, and activity impairment in moderate-to-severe HS patients.

Comorbidity screening in hidradenitis suppurativa: Evidence-based recommendations from the US and Canadian Hidradenitis Suppurativa Foundations.

BACKGROUND: Hidradenitis suppurativa (HS) is associated with comorbidities that contribute to poor health, impaired life quality, and mortality risk. OBJECTIVE: To provide evidence-based screening recommendations for comorbidities linked to HS. METHODS: Systematic reviews were performed to summarize evidence on the prevalence and incidence of 30 comorbidities in patients with HS relative to the general population. The screening recommendation for each comorbidity was informed by the consistency and quality of existing studies, disease prevalence, and magnitude of association, as well as benefits, harms, and feasibility of screening. The level of evidence and strength of corresponding screening recommendation were graded by using the Strength of Recommendation Taxonomy (SORT) criteria. RESULTS: Screening is recommended for the following comorbidities: acne, dissecting cellulitis of the scalp, pilonidal disease, pyoderma gangrenosum, depression, generalized anxiety disorder, suicide, smoking, substance use disorder, polycystic ovary syndrome, obesity, dyslipidemia, diabetes mellitus, metabolic syndrome, hypertension, cardiovascular disease, inflammatory bowel disease, spondyloarthritis, and sexual dysfunction. It is also recommended to screen patients with Down syndrome for HS. The decision to screen for specific comorbidities may vary with patient risk factors. The role of the dermatologist in screening varies according to comorbidity. LIMITATIONS: Screening recommendations represent one component of a comprehensive care strategy. CONCLUSIONS: Dermatologists should support screening efforts to identify comorbid conditions in HS.

Laying the foundation for Real-world evidence studies: a case study from Newfoundland and Labrador.

The Janssen and Newfoundland and Labrador Health Innovation Partnership (JANL-HIP) was established to carry out Real-World Evidence (RWE) projects to generate evidence about disease pathways, healthcare delivery, the effects of clinical interventions. Doing so will support and influence clinical decision-making in Newfoundland and Labrador (NL). This case study describes the foundational elements necessary for a real-world evidence generation project in NL and may provide learning for the effective execution of real-world studies in other jurisdictions. It uses an ongoing project in psoriatic disease in NL to illustrate the partnership and the benefits of RWE studies. Ultimately, the JANL-HIP RWE project aims to inform decisions that will drive improvements in health outcomes, system delivery, and policy mutually beneficial to health ecosystem stakeholders.

Moderate-to-severe plaque psoriasis patients treated with ixekizumab: early real-world outcomes and adverse events.

INTRODUCTION: Data on real-world experiences for patients treated with ixekizumab is currently limited. OBJECTIVES: Describe characteristics of ixekizumab-treated psoriasis patients and provide evidence of clinical outcomes using disease severity scores Body Surface Area (BSA) and Psoriasis Area and Severity Index (PASI) in the real world. METHODS: Chart review was performed for adult patients treated with ixekizumab at a single Canadian dermatology clinic (February 2017-August 2018). The cohort was stratified into responders (patients who remained on ixekizumab) and non-responders (patients who discontinued ixekizumab). Subgroup analyses were performed for responders to assess clinical improvement stratified by previous biologic exposure. RESULTS: Thirty-eight patients were included (mean observational time 32 weeks). At baseline, mean PASI and BSA were 10.8 and 11.6%, respectively. Mean changes in PASI and BSA were -7.8 and -6.7%, respectively, at week 4. PASI 100 was achieved in 70% of patients. Significant differences in mean change of BSA were seen between bio-naïve and bio-experienced patients. CONCLUSION: This analysis represents the first investigation of early clinical outcomes in a small cohort of Canadian patients treated with ixekizumab. Overall, complete and rapid skin clearance was observed. Future studies including more patients and longer follow-up time are crucial to confirm these findings.

The Incidence of Cutaneous Malignant Melanoma in Eastern Newfoundland and Labrador, Canada, from 2007 to 2015.

BACKGROUND: The incidence of cutaneous malignant melanoma continues to increase worldwide and in Canada. It is unclear whether the increase in incidence and clinical characteristic trends of cutaneous malignant melanoma are similar in the province of Newfoundland and Labrador. OBJECTIVE: The objective of this study is to examine the incidence and trends of cutaneous malignant melanoma in Eastern Newfoundland and Labrador. METHODS: Patients aged 18 years or older diagnosed with cutaneous malignant melanoma were identified from the Eastern Health Authority's Cancer Registry. The diagnosis was confirmed by a pathologist via histological subtype. Patients were excluded if the diagnosis was unspecified, a nonmelanoma skin cancer or if there was a recurrence in the same lesion location. In total 298 patients diagnosed with cutaneous malignant melanoma from 2007 to 2015 were included in the analysis. RESULTS: The total incidence increased from 4.1 to 15.6 cases/100,000 person-years, which represents a 283.0% increase from 2007 to 2015. The largest increases in incidence were seen in males and patients aged from 60 to 79 years. The most common lesion anatomical locations were the trunk in males and the lower extremity in females. The majority of cases had a Breslow thickness below 1.0 mm. CONCLUSION: The incidence of cutaneous malignant melanoma in Eastern Newfoundland and Labrador is increasing at a faster rate than in any other region in Canada. Health care providers should work to be aware of the clinical trends and risk factors associated with this disease to facilitate early detection and prevent morbidity.

Prevalence of Hidradenitis Suppurativa: A Systematic Review and Meta-regression Analysis.

IMPORTANCE: Hidradenitis suppurativa/acne inversa (HS) is a chronic inflammatory skin disease characterized by occlusion of hair follicles as a primary pathogenic factor. There are scarce data regarding the prevalence of HS. OBJECTIVE: To estimate overall HS prevalence. DATA SOURCES: This review and meta-regression analysis was conducted using the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline. The academic search included PubMed, Cochrane registry, ClinicalTrials.gov, and evidence by NHS UK and Trip databases from inception through May 2020. To analyze HS prevalence, only cross-sectional studies or baseline assessments of longitudinal cohorts using census-based surveys or probabilistic and nonprobabilistic epidemiologic methods were considered. The search terms were (prevalence OR incidence OR epidemiology) AND (hidradenitis suppurativa OR acne inversa OR Verneuil's disease). No language restriction was applied. STUDY SELECTION: Original investigations that reported HS prevalence were included. After exclusion criteria were applied, 17 studies qualified for qualitative analysis, but only 16 studies were quantitatively assessed. DATA EXTRACTION AND MEASURES: Two reviewers extracted data by age, diagnostic criteria, presence of any comorbidity, sample sizes, continent/location, sex, and other characteristics. Assessment of bias risk used the Joanna Briggs Institute Critical Appraisal Instrument for Studies Reporting Prevalence Data using random-effects models to synthesize available evidence. MAIN OUTCOMES AND MEASURES: Hidradenitis suppurativa prevalence (with 95% CI) among the overall population and among subgroups. Between-study heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). RESULTS: In 16 quantitatively assessed studies included, prevalence estimates were reported only from Western European and Scandinavian countries, the US, and Australia. Meta-analysis with random effects, after adjusting for publication bias in the prevalence estimates, revealed a 0.40% prevalence (95% CI, 0.26%-0.63%) for HS. Studies based on clinical samples revealed a higher pooled prevalence of HS (1.7%) than population-based studies (0.3%). CONCLUSIONS AND RELEVANCE: The findings of this systematic review and meta-regression analysis may help facilitate policy formulation, channeling funding and guiding principles for better disease diagnosis using universal valid tools and management.

Investigation of prevalence of biologic use and discontinuation rates in moderate-to-severe psoriasis patients in Newfoundland and Labrador using real-world data.

Real-world data for psoriasis includes registries, and meta-analyses could help guide biologic therapy choice. The objective was to determine the prevalence and reason for discontinuation of biologic or PD4 inhibitor therapy in patients with moderate-to-severe psoriasis in Newfoundland and Labrador, Canada from 2001 to 2017. A retrospective cohort study was conducted on data collected between 2001 and 2017, to determine the type of biologic therapy or PD4 inhibitor, length of treatment, prevalence of and reason for discontinuation. As multiple patients have been on more than one therapy (ie, an average of 1.8), the 459 patients included in the registry have had a total of 913 exposures to biologic or PD4 inhibitors. The treatment mean time was 37 months (SD 39.95). A total of 180 patients remained on their first biologic of which 75% were male. The average number of biologics per patient was 1.99. The reasons for discontinuation were primary failure (28.5%), adverse events (26.4%), secondary failure (24.3%), patient choice (4.4%), other/unknown in (6.6%), drug withdrawal from market (6.8%), and drug coverage issues (3%). The most common reasons for discontinuation of biologics or PD4 inhibitors include primary failure, adverse events, and secondary failures. Males were more likely to remain on their first biologic.