Undiagnosed Psoriatic Arthritis Research Articles

Enhanced surveillance for the detection of psoriatic arthritis in a UK primary care psoriasis population: results from the TUDOR trial.

Our objective was to determine whether early detection of undiagnosed psoriatic arthritis (PsA) in a primary care psoriasis population improves outcome in physical function at 24 months post-registration. A multicentre, prospective, parallel group cluster randomised controlled trial in patients with psoriasis was conducted. Participants with suspected inflammatory arthritis on screening were referred for an assessment of PsA (enhanced surveillance (ES) arm: at baseline, 12 and 24 months; standard care (SC) arm: at 24 months). The primary outcome measure was the Health Assessment Questionnaire Disability Index (HAQ-DI) at 24 months post registration in participants diagnosed with PsA. A total of 2225 participants across 135 GP practices registered: 1123 allocated to ES and 1102 to SC. The primary analysis population consisted of 87 participants with a positive diagnosis of PsA: 64 in ES, 23 in SC. The adjusted odds ratio (OR) for achieving a HAQ-DI score of 0 at 24 months post registration in ES compared with SC was 0.64 (95% CI (0.17, 2.38)), and the adjusted OR of achieving a higher (non-zero) HAQ-DI score at 24 months post registration in ES relative to SC arm was 1.12 (95% CI: 0.67, 1.86), indicating no evidence of a difference between the two treatment groups (p= 0.66). The trial was underpowered for demonstrating the prespecified treatment effect; in patients with psoriasis there was no evidence that early diagnosis of PsA by ES in primary care changes physical function at 24 months compared with SC. The TUDOR trial is registered as ISRCTN38877516.

Successful Screening of Undiagnosed Psoriatic Arthritis in Primary Care Utilising Digital Interventions Within a Quality Improvement Programme

Background: Despite the advancements in the management of psoriasis (PsO) and psoriatic arthritis (PsA), there remains a significant delay to diagnosis of PsA. National guidelines recommend regular screening of patients with PsO for PsA. The aim of this study was to increase the screening of patients with PsO, and reduce the delay to diagnosis in PsA. Methods: A retrospective baseline audit was conducted in patients with PsO attending a large general practice (Brookside Group Practice, Reading, UK) between November 2022–April 2023. In the follow-up stage between May–November 2023, a digital Egton Medical Information System (EMIS; Emis Health, Rawdon, Leeds, UK) web template, using the Psoriasis Epidemiology Screening Tool (PEST) questionnaire was implemented. The number of patients with PsO screened for PsA, and the number of newly diagnosed PsA cases, were recorded. Results: At baseline, 15 patients with PsO were identified, and none had PsA screening done. In the follow-up phase, 28 patients coded for PsO were identified. There was an increase in the number of patients screened for PsO from 15 to 28, representing an increase of 87% from baseline. From the follow-up group, 12 (43%) patients were screened for PsA. These patients were referred to the specialist clinic, and seven (58%) had confirmed PsA. This represented a population of patients with previously undiagnosed PsA within the general practitioner (GP) surgery. Conclusions: The authors have successfully implemented an integrated and interactive digital screening tool for PsA within the GP system. This has led to an increase in the detection of patients with PsA. This practical and effective approach is in line with national guidelines for early detection, to prevent long-term damage and disability from PsA.

Successful Screening of Undiagnosed Psoriatic Arthritis in Primary Care Utilising Digital Interventions Within a Quality Improvement Programme

Background: Despite the advancements in the management of psoriasis (PsO) and psoriatic arthritis (PsA), there remains a significant delay to diagnosis of PsA. National guidelines recommend regular screening of patients with PsO for PsA. The aim of this study was to increase the screening of patients with PsO, and reduce the delay to diagnosis in PsA. Methods: A retrospective baseline audit was conducted in patients with PsO attending a large general practice (Brookside Group Practice, Reading, UK) between November 2022–April 2023. In the follow-up stage between May–November 2023, a digital Egton Medical Information System (EMIS; Emis Health, Rawdon, Leeds, UK) web template, using the Psoriasis Epidemiology Screening Tool (PEST) questionnaire was implemented. The number of patients with PsO screened for PsA, and the number of newly diagnosed PsA cases, were recorded. Results: At baseline, 15 patients with PsO were identified, and none had PsA screening done. In the follow-up phase, 28 patients coded for PsO were identified. There was an increase in the number of patients screened for PsO from 15 to 28, representing an increase of 87% from baseline. From the follow-up group, 12 (43%) patients were screened for PsA. These patients were referred to the specialist clinic, and seven (58%) had confirmed PsA. This represented a population of patients with previously undiagnosed PsA within the general practitioner (GP) surgery. Conclusions: The authors have successfully implemented an integrated and interactive digital screening tool for PsA within the GP system. This has led to an increase in the detection of patients with PsA. This practical and effective approach is in line with national guidelines for early detection, to prevent long-term damage and disability from PsA.

JAAD Game Changer: “Prevalence of undiagnosed psoriatic arthritis among psoriasis patients: Systematic review and meta-analysis”

JAAD Game Changer: “Prevalence of undiagnosed psoriatic arthritis among psoriasis patients: Systematic review and meta-analysis”

Evaluation of a machine learning tool for the early identification of patients with undiagnosed psoriatic arthritis – A retrospective population-based study

BackgroundPsoriatic arthritis (PsA), an immune-mediated chronic inflammatory skin and joint disease, affects approximately 0.27% of the adult population, and 20% of patients with psoriasis. Up to 10% of psoriasis patients are estimated for having undiagnosed PsA. Early diagnosis and treatment can prevent irreversible joint damage, disability and deformity. Questionnaires for screening to identify undiagnosed PsA patients require patient and physician involvement. ObjectiveTo evaluate a proprietary machine learning tool (PredictAI™) developed for identification of undiagnosed PsA patients 1–4 years prior to the first time that they were suspected of having PsA (reference event). MethodsThis retrospective study analyzed data of the adult population from Maccabi Healthcare Service between 2008 and 2020. We created 2 cohorts: The general adult population (“GP Cohort”) including patients with and without psoriasis and the Psoriasis cohort (“PsO Cohort”) including psoriasis patients only. Each cohort was divided into two non-overlapping train and test sets. The PredictAI™ model was trained and evaluated with 3 years of data predating the reference event by at least one year. Receiver operating characteristic (ROC) analysis was used to investigate the performance of the model, built using gradient boosted trees, at different specificity levels. ResultsOverall, 2096 patients met the criteria for PsA. Undiagnosed PsA patients in the PsO cohort were identified with a specificity of 90% one and four years before the reference event, with a sensitivity of 51% and 38%, and a PPV of 36.1% and 29.6%, respectively. In the GP cohort and with a specificity of 99% and for the same time windows, the model achieved a sensitivity of 43% and 32% and a PPV of 10.6% and 8.1%, respectively. ConclusionsThe presented machine learning tool may aid in the early identification of undiagnosed PsA patients, and thereby promote earlier intervention and improve patient outcomes.

Machine Learning Approaches for Predicting Psoriatic Arthritis Risk Using Electronic Medical Records: Population-Based Study.

Psoriasis (PsO) is a chronic, systemic, immune-mediated disease with multiorgan involvement. Psoriatic arthritis (PsA) is an inflammatory arthritis that is present in 6%-42% of patients with PsO. Approximately 15% of patients with PsO have undiagnosed PsA. Predicting patients with a risk of PsA is crucial for providing them with early examination and treatment that can prevent irreversible disease progression and function loss. The aim of this study was to develop and validate a prediction model for PsA based on chronological large-scale and multidimensional electronic medical records using a machine learning algorithm. This case-control study used Taiwan's National Health Insurance Research Database from January 1, 1999, to December 31, 2013. The original data set was split into training and holdout data sets in an 80:20 ratio. A convolutional neural network was used to develop a prediction model. This model used 2.5-year diagnostic and medical records (inpatient and outpatient) with temporal-sequential information to predict the risk of PsA for a given patient within the next 6 months. The model was developed and cross-validated using the training data and was tested using the holdout data. An occlusion sensitivity analysis was performed to identify the important features of the model. The prediction model included a total of 443 patients with PsA with earlier diagnosis of PsO and 1772 patients with PsO without PsA for the control group. The 6-month PsA risk prediction model that uses sequential diagnostic and drug prescription information as a temporal phenomic map yielded an area under the receiver operating characteristic curve of 0.70 (95% CI 0.559-0.833), a mean sensitivity of 0.80 (SD 0.11), a mean specificity of 0.60 (SD 0.04), and a mean negative predictive value of 0.93 (SD 0.04). The findings of this study suggest that the risk prediction model can identify patients with PsO at a high risk of PsA. This model may help health care professionals to prioritize treatment for target high-risk populations and prevent irreversible disease progression and functional loss.

Assessment of four screening tools and retrieval of key questions to detect undiagnosed psoriatic arthritis in Chinese patients with psoriasis: A multicenter study.

Several screening tools have been developed to facilitate early diagnosis of psoriatic arthritis (PsA); however, their performance varied greatly across different studies. In this study, we validated and compared the performance of four screening tools in detecting undiagnosed PsA Chinese patients with psoriasis, and determined the key questions and their weights. The four screening tools were the Early Arthritis for Psoriatic Patients (EARP) questionnaire, Psoriatic Arthritis Screening and Evaluation (PASE) questionnaire, Psoriasis and Arthritis Screening Questionnaire (PASQ), and Psoriasis Epidemiology Screening Tool (PEST). The receiver-operator curve (ROC) with area under curve (AUC) was used to determine sensitivity, specificity, and accuracy. Least absolute shrinkage and selection operator and logistic regression were utilized to retrieve key questions, and a nomogram was utilized to visualize their weights. Of 482 psoriasis patients from dermatology clinics, 77 were newly diagnosed with PsA. Another 68 patients with newly diagnosed PsA from rheumatology clinics were incorporated in the analysis. ROC analysis indicated that the optimal cut-off values for EARP, PASE, PASQ, and PEST were 3, 40, 7, and 3, with corresponding sensitivities of 91.4%, 88.6%, 86.2%, and 88.5%, and specificities of 88.6%, 75.2%, 80.2%, and 83.6%, respectively. The AUC of EARP (0.925) was higher than those of PASE (0.885), PASQ (0.905), and PEST (0.827). However, none of them were sufficiently sensitive to identify pure axial PsA (sensitivities of EARP, PASQ, and PASE were 25.0%, 36.8%, and 42.1%, respectively). Twelve key questions were retrieved from these four tools to establish a nomogram with a high discrimination (C-index=0.993) and a good calibration (mean absolute error=0.014). In conclusion, to screen undiagnosed PsA, EARP has slightly better balanced sensitivity and specificity, and higher accuracy. The retrieval of key questions and nomogram signify the necessity of attributing different scores to differently weighted questions when developing a new screening tool to make it function more efficiently.

Perceptions of Rheumatologists on Diagnosis of Psoriatic Arthritis in China.

ObjectiveHigh prevalence of undiagnosed psoriatic arthritis (PsA) and prolonged diagnostic delay are key troubles in the appropriate management of PsA. To analyze the possible causes for this phenomenon, a web-based nationwide survey was conducted to investigate rheumatologists’ perceptions on PsA diagnosis in China.MethodsThe electronic questionnaire consisting of 38 questions were designed by an expert panel and distributed with the online survey tool Sojump, which is a professional online survey platform. The completed questionnaires by real-name rheumatologists were collected.ResultsA total of 1594 valid questionnaires were included. More than half of Chinese rheumatologists reported it was challenging to make a diagnosis of PsA. The four major challenges were “Difficulties in identification of atypical or hidden psoriasis”, “Absence of diagnostic biomarkers”, “No active self-report of history or family history of psoriasis” and “Various musculoskeletal manifestations”. In diagnosing PsA, minor participants had incorrect knowledge of inflammatory arthropathy (13.7%), acute phase reactant (23.8%), and rheumatoid factor (28.7%). There were no significant differences in the knowledge of PsA and practice habits in diagnosing PsA between modern western medicine (WM)- and traditional Chinese medicine (TCM)-rheumatologists. The part-time rheumatologists were not as good as full-time rheumatologists in diagnosing PsA.ConclusionsAbout three quarters of Chinese rheumatologists are familiar with the elements in PsA diagnosis and have good practice habits in diagnosing PsA. Four main challenges in making PsA diagnosis are revealed. There was no significant difference in the knowledge of PsA between WM- and TCM-rheumatologists.

384 Differences in musculoskeletal impact on health among patients with psoriasis based on disease type, disease severity and undiagnosed psoriatic arthritis (PsA)

384 Differences in musculoskeletal impact on health among patients with psoriasis based on disease type, disease severity and undiagnosed psoriatic arthritis (PsA)

Utilization of the validated Psoriasis Epidemiology Screening Tool to identify signs and symptoms of psoriatic arthritis among those with psoriasis: a cross-sectional analysis from the US-based Corrona Psoriasis Registry.

BackgroundDespite increasing awareness of the disease, rates of undiagnosed psoriatic arthritis (PsA) are high in patients with psoriasis (PsO). The validated Psoriasis Epidemiology Screening Tool (PEST) is a five‐item questionnaire developed to help identify PsA at an early stage.ObjectivesTo assess the risk of possible undiagnosed PsA among patients with PsO and characterize patients based on PEST scores.MethodsThis study included all patients enrolled in the Corrona PsO Registry with data on all five PEST questions. Demographics, clinical characteristics and patient‐reported outcomes were compared in Corrona PsO Registry patients with PEST scores ≥3 and <3 using t‐tests for continuous variables and chi‐squared tests for categorical variables; scores ≥3 may indicate PsA.ResultsOf 1516 patients with PsO, 904 did not have dermatologist‐reported PsA; 112 of these 904 patients (12.4%) scored ≥3 and were significantly older, female, less likely to be working, and had higher BMI than patients with scores <3. They also had significantly longer PsO duration, were more likely to have nail PsO and had worse health status, pain, fatigue, Dermatology Life Quality Index and activity impairment.ConclusionsImproved PsA screening is needed in patients with PsO because the validated PEST identified over one‐tenth of registry patients who were not noted to have PsA as having scores ≥3, who could have had undiagnosed PsA. Appropriate, earlier care is important because these patients were more likely to have nail PsO, worse health‐related quality of life and worse activity impairment.

ENTHESITIS AND PSORIATIC ONYCHOPATHY AS A FACTOR FOR PREDICTION OF PSORIATIC ARTHRITIS IN PSORIASIS

Psoriatic arthritis is a psoriasis-related spondyloarthropathy that occurs in 20–30 % of patients with psoriasis. Psoriatic arthritis affects the patient’s quality of life indicators and are more often associated with disabilities of working age than psoriasis skin form. Nail psoriasis has been proposed as a predictor for the development of psoriatic arthritis. The inflammation involving the entheses, called enthesitis, is an early inflammatory change seen in psoriatic arthritis, and nail changes appear to result from the close relationship between the nail and the enthesis of the distal interphalangeal extensor tendon, one of the main entheseal compartments affected in psoriatic arthritis. Various imaging studies have demonstrated that there is a considerable proportion of undiagnosed psoriatic arthritis among patients with psoriasis. Since early detection and treatment of psoriatic arthritis could, ultimately, allow the prevention of clinical and radiologic progression of the disease, there is the need to establish clinical indicators to detect this risk.

Clinical case report: Unusual and severe psoriatic arthritis mutilans

Psoriatic Arthritis (PsA) is considered part of the spondyloarthritis group, which is present in up to 42% of individuals with psoriasis and up to 15% of patients with psoriasis may have undiagnosed PsA. Psoriatic arthritis Mutilans is a rare but very aggressive type of advanced joint disease in patients with psoriasis. This report describes the case of a 67 years old patient with family history of psoriasis and undiagnosed psoriatic arthritis with nail lesions for more than 16 years, arthritis for 15 years and severe disease during the last 3 years with disability and bedridden. She had serious joint complications of the disease, as well as severe malnutrition. A missdiagnosis of rheumatoid arthritis was given during 15 years, HLAB27 was positive and radiography of hands and feet showed classic findings of psoriatic arthritis mutilans. We present this case to show the severity of the disease with rapid progression and multiple additional joint complications.

An educational leaflet improves response to invitation for screening for arthritis in patients with psoriasis in primary care, but only in practices in the most deprived areas

This study hypothesises that an educational leaflet about psoriatic arthritis (PsA) will improve psoriasis patients’ attendance for screening for PsA. A random sample of patients ≥18 years old with a coded diagnosis of psoriasis and no diagnosis of PsA, rheumatoid arthritis or ankylosing spondylitis were identified from five GP surgeries in Yorkshire, UK. Patients were randomised 1:1 to receive study information alone or with the educational leaflet, with an invitation to attend for a screening examination by a dermatologist and rheumatologist. Nine hundred thirty-two invitation packs were sent to recruit 191 (20.5%) participants. One hundred sixty-nine (88.5%) had current or previous psoriasis and 17 (10.1%) had previously undiagnosed PsA. The estimated prevalence of PsA was 18.1% (95% CI: 16.2, 20.1%).The response rate was lower than expected and was not significantly higher when patients received the educational leaflet (22.8 vs 18.3%, p = 0.08). Response rates varied by practice (14.7 to 30.6%). However, deprivation scores for each practice revealed a significant increase in response with the leaflet for deprivation decile of 3 (p < 0.001) but no significant differences in the other practices. An educational leaflet about PsA improves attendance for screening in primary care, but only in those practices with higher levels of socioeconomic deprivation.

Frequency of undiagnosed psoriatic arthritis among psoriasis patients in Australian dermatology practice.

Psoriatic arthritis commonly develops in psoriasis patients and, if undiagnosed, can lead to potentially avoidable joint damage and an increased risk of comorbidity and mortality. Increased awareness of PsA symptoms among dermatologists provides an opportunity for earlier diagnosis, more timely therapy and prevention of disability. To provide Australian epidemiological data on the frequency of undiagnosed PsA among psoriasis patients in dermatology practice, and to investigate the impact of psoriasis on quality of life and work productivity. Nine tertiary centre dermatology practices enrolled patients presenting with plaque psoriasis and no prior rheumatologist-confirmed PsA diagnosis. Patients were screened using the Psoriatic Arthritis Screening and Evaluation (PASE) questionnaire and were referred to a rheumatologist for assessment of PsA status using CASPAR criteria if they had a PASE score ≥44. Based on the composite and sequential application of PASE and CASPAR criteria, undiagnosed PsA among psoriasis patients in this study is 9% [95% CI: 6, 12]. The PPV of PASE in this setting is 26% [95% CI: 19, 34]. Nail involvement and chronic large plaque psoriasis were identified as independent positive predictors of PsA, whereas scalp psoriasis was an independent negative predictor of PsA. Patients with moderate-to-severe psoriasis (PASI ≥15) had lower quality of life scores than patients with less severe psoriasis. In this study, the frequency of undiagnosed PsA in Australian dermatology practice was 9% among plaque psoriasis patients with no prior PsA diagnosis. Compared with psoriasis alone, the impact of undiagnosed PsA on health-related quality of life of psoriasis patients is substantial.

Nail psoriasis as a predictor of the development of psoriatic arthritis

Psoriatic arthritis is a psoriasis-related spondyloarthropathy that occurs in 20–30% of patients with psoriasis. Various imaging studies have demonstrated that there is a considerable proportion of undiagnosed psoriatic arthritis among patients with psoriasis. Since early detection and treatment of psoriatic arthritis could, ultimately, allow the prevention of clinical and radiologic progression of the disease, there is the need to establish clinical indicators to detect this risk.Nail psoriasis has been proposed as a predictor for the development of psoriatic arthritis. The inflammation involving the entheses, called enthesitis, is an early inflammatory change seen in psoriatic arthritis, and nail changes appear to result from the close relationship between the nail and the enthesis of the distal interphalangeal extensor tendon, one of the main entheseal compartments affected in psoriatic arthritis.As skin lesions precede articular symptoms in more than 75–80% of patients with psoriatic arthritis, dermatologists may play a key role in the early detection and management of psoriatic arthritis.

Prevalence of undiagnosed psoriatic arthritis among psoriasis patients: Systematic review and meta-analysis

Skin psoriasis precedes the onset of psoriatic arthritis (PsA) in 84% of patients with psoriasis. Dermatologists have an important role to screen psoriasis patients for PsA. The efficiency of PsA screening remains unknown. We sought to determine the point prevalence of undiagnosed PsA in patients with psoriasis using a systematic search of the literature and meta-analysis. PubMed, Cochrane, and Embase database searches yielded 394 studies for review. No study aimed to determine the prevalence of undiagnosed PsA in patients with psoriasis. We assumed that the prevalence of newly diagnosed PsA in patients with psoriasis at the time they seek medical care could be a sound estimate of this value. Seven epidemiological studies and 5 studies on PsA screening questionnaires allowed us to clearly identify patients with newly diagnosed PsA and were selected for review. The prevalence of undiagnosed PsA was 15.5% when all studies were considered and 10.1% when only epidemiological studies were considered. Data were obtained from studies not designed to address the question at hand. Heterogeneity was high (I(2)=96.86%), and therefore a random effects model was used. The high prevalence of undiagnosed PsA in patients with psoriasis adds to the recommendation that dermatologists need to screen all patients with psoriasis for PsA.

Nail psoriasis as a predictor of the development of psoriatic arthritis

Psoriatic arthritis is a psoriasis-related spondyloarthropathy that occurs in 20–30% of patients with psoriasis. Various imaging studies have demonstrated that there is a considerable proportion of undiagnosed psoriatic arthritis among patients with psoriasis. Since early detection and treatment of psoriatic arthritis could, ultimately, allow the prevention of clinical and radiologic progression of the disease, there is the need to establish clinical indicators to detect this risk.Nail psoriasis has been proposed as a predictor for the development of psoriatic arthritis. The inflammation involving the entheses, called enthesitis, is an early inflammatory change seen in psoriatic arthritis, and nail changes appear to result from the close relationship between the nail and the enthesis of the distal interphalangeal extensor tendon, one of the main entheseal compartments affected in psoriatic arthritis.As skin lesions precede articular symptoms in more than 75–80% of patients with psoriatic arthritis, dermatologists may play a key role in the early detection and management of psoriatic arthritis.

Quantitative tandem mass-spectrometry of skin tissue reveals putative psoriatic arthritis biomarkers.

BackgroundPsoriatic arthritis (PsA) is a distinct inflammatory arthritis occurring in 30% of psoriasis patients. There is a high prevalence of undiagnosed PsA in psoriasis patients; therefore, identifying soluble biomarkers for PsA could help in screening psoriasis patients for appropriate referral to a rheumatologist. Potential PsA biomarkers likely originate in sites of inflammation, such as the skin, and subsequently enter systemic circulation. Our goal was to identify candidate PsA biomarkers by comparing the proteome of skin biopsies obtained from patients with PsA to that from patients with psoriasis without PsA.MethodsSkin biopsies were obtained from involved and uninvolved skin of 10 PsA and 10 age/gender-matched psoriasis patients without PsA (PsC). Using strong cation exchange chromatography, followed by label-free quantitative tandem mass spectrometry, we characterized the proteomes of pooled skin samples. Extracted ion current intensities were used to calculate protein abundance ratios, and these were utilized to identify differentially regulated proteins.ResultsForty-seven proteins were elevated in PsA-derived skin compared to PsC-derived skin. Selected reaction monitoring assays were developed to quantify these potential PsA markers in individual skin samples, and 8 markers were confirmed in an independent sample set. ITGB5 and POSTN were measured in serum samples from 33 PsA and 15 PsC patients, using enzyme-linked immunosorbent assays. ITGB5 was significantly elevated in PsA serum (P < 0.01), and POSTN showed a trend. ITGB5 and POSTN correlated significantly in both patient groups (r = 0.472, P < 0.001).ConclusionProteomic analysis of PsA and PsC skin identified eight new candidate biomarkers. These markers need to be validated with a larger and independent cohort, in order to delineate their clinical utility in PsA patients. These proteins may also uncover unknown aspects of PsA pathobiology.Electronic supplementary materialThe online version of this article (doi:10.1186/1559-0275-12-1) contains supplementary material, which is available to authorized users.

High prevalence of psoriatic arthritis in patients with severe psoriasis with suboptimal performance of screening questionnaires

ObjectivesThe objectives of this study were to: (1) assess the prevalence of psoriatic arthritis (PsA) among Psoriasis (Ps) patients attending dermatology clinics; (2) identify clinical predictors of the development of...

The Burden of Psoriasis in Canada: Insights from the pSoriasis Knowledge IN Canada (SKIN) Survey

Although some data addressing the burden of illness associated with psoriasis and psoriatic arthritis (PsA) have been reported for American and European patient populations, similar data have been lacking for Canadians with these diseases. We sought to characterize the natural history of disease in a sample of Canadians with a history of moderate to severe psoriasis, with or without diagnosed PsA or other recognized comorbid conditions, and to identify factors that influenced their perception of psoriasis as a problem in their daily lives. A nationwide telephone survey, pSoriasis Knowledge IN Canada (SKIN), was conducted between April 30 and June 2, 2007, on 500 people who indicated that they had been diagnosed with psoriasis and that their skin lesions had at some time affected an area at least as large as three palms of their hand (3% of body surface area [BSA]). The mean age at diagnosis for psoriasis among SKIN survey respondents was 28 years, with 31% (155 of 500) indicating that they developed the disease prior to age 18 years. At the time of the survey, 54% (269 of 500) of respondents were experiencing lesions affecting a BSA equivalent to at least three palms (3%). In response to questions on the burden of illness, 35% (176 of 500) of respondents indicated that they considered psoriasis to be a substantial problem in their daily life. Both affected BSA at the time of the survey and self-reported extent of skin involvement at the height of the condition (BSAmax) correlated with the perception of psoriasis as a substantial problem. Other subpopulations in which psoriasis was commonly identified as a substantial problem included women and individuals with diagnosed PsA. Whereas 18% (88 of 500) of respondents were diagnosed with PsA, the number who reported joint pain or stiffness was substantially higher (51%; 256 of 500), suggesting that some respondents may have had incipient or undiagnosed PsA. This survey reveals that psoriasis, PsA, and their associated comorbidities impose a severe burden on the daily lives of Canadians with a history of moderate to severe psoriasis.