Title: Diagnosing childhood psoriasis: developing diagnostic criteria
Funder: Department of Health and Social Care

Abstract: Background This study will develop diagnostic criteria for psoriasis in children ( The diagnosis of psoriasis in children is more challenging than in adults. Diagnostic difficulties occur because the clinical signs in children are under-recognised by health professionals, often morphologically different to adults, occur in covered body sites and can be misdiagnosed as other common childhood skin rashes such as eczema and fungal skin infections. Research objectives Stage 1: To develop expert-derived diagnostic criteria for childhood psoriasis Stage 2: To test the diagnostic ability of the criteria in UK dermatology clinics and refine the criteria Stage 3: To ensure the diagnostic criteria are easy to understand by potential users Stage 4: Feasibility testing of a self/parent-complete diagnostic criteria questionnaire Stage 5: To develop a proposal for an epidemiological study on childhood psoriasis Plan of investigation An electronic Delphi (eDelphi) consensus study with the International Psoriasis Council will agree a list of diagnostic criteria for psoriasis in children (stage 1). The eDelphi will involve a series of online surveys to score diagnostic features. Consensus will be defined as >70% agreement that a feature is important for the diagnosis of psoriasis. The diagnostic ability of the agreed diagnostic set will be tested in a multi-centre paediatric dermatology case-control study (stage 2). Cases will be defined as children with a dermatologist's diagnosis of psoriasis and controls children with a confirmed diagnosis of another inflammatory skin. Multivariate conditional logistic regression modelling will be used to determine the best predictive model to diagnose psoriasis. At this stage redundant diagnostic features will be removed from the diagnostic criteria. Patients, GPs and paediatric rheumatologists will be involved in modifying the wording of the revised diagnostic criteria to ensure usability by all stakeholders through face-to face meetings and think-aloud interviews (stage 3). The feasibility of using a diagnostic criteria questionnaire for epidemiological studies will be tested in paediatric dermatology clinics on children with all types of skin disease (stage 4). Feasibility testing will provide provisional quantitative data on the diagnostic accuracy of the questionnaire and qualitative results on the ease of completion. This work will lead to a proposal for an epidemiological study using the diagnostic criteria (Stage 5) as part of the Global Psoriasis Atlas. Potential benefit to patients and the NHS Improved recognition and diagnosis of psoriasis will ensure children receive psoriasis specific treatment and monitoring for associated diseases such as arthritis. Early diagnosis of juvenile psoriatic arthritis and effective treatment prevents permanent joint damage and disability. At present up to 90% of children with psoriasis are misdiagnosed. Standardisation of the definition of psoriasis will help meta-analysis of studies; thereby reducing research wastage. Training and development The fellowship will be undertaken at the internationally recognised Centre of Evidence Based Dermatology and include an MSc in Epidemiology; supporting my career development to become a dermato-epidemiologist.

Lay abstract: Why is this research needed? Psoriasis is a skin condition that can cause red, flaky patches on any part of the body including the face, scalp, hands and genitals. Children with psoriasis can develop an inflammatory arthritis leading to swelling, discomfort and permanent joint damage. Psoriasis may also lead to obesity and long-term health problems such as high blood pressure and diabetes. It is therefore important that psoriasis is diagnosed accurately and early, so that specific treatment and monitoring can be started. Psoriasis is often difficult to diagnose in children. Research shows that up to nine in ten children with psoriasis are mistakenly diagnosed with other skin conditions by non-dermatologists. This study aims to develop diagnostic criteria for psoriasis in children (under 18 years). The criteria must be suitable for use by a wide range of health professionals and for research studies. What are the important questions that will be answered? 1)Which are the most important skin signs to look for and questions to ask (diagnostic criteria) to make a diagnosis of psoriasis? 2)How well do the diagnostic criteria perform and can the criteria be refined? 3)How can the diagnostic criteria be made simpler to understand by non-specialists? 4)How can the diagnostic criteria be used as a questionnaire for young people or parents to complete? 5)How can the diagnostic criteria be used in future research studies? How will the research be done? First, a group of international psoriasis experts will be asked to agree a list of diagnostic criteria in an eDelphi consensus study. Agreement will be reached by asking them to suggest and score diagnostic features that should be included. Diagnostic features that are agreed as important by most experts will included in the criteria. In stage 2, the agreed diagnostic criteria will be evaluated in children with skin conditions including psoriasis in a study type called a case-control study. This study will assess how well the criteria perform at diagnosing psoriasis. The results will be used in a statistical model to refine the diagnostic criteria by removing those that poorly predicted psoriasis. Stage 3 will involve meetings and interviews with patient advisors, young people and a range of health professionals to simplify the wording of the diagnostic criteria. The aim will be to produce a single set of diagnostic criteria that are easy to understand by patients and health professionals without specific dermatological training. In stage 4 the suitability of a diagnostic criteria questionnaire for young people or parents to complete will be assessed. This will happen by testing the questionnaire on patients attending dermatology clinics with a wide variety of skin conditions. The findings from all stages will contribute to the design of a large study (stage 5) looking to answer questions important to patients such as how common is psoriasis' and what will happen to my psoriasis?' Where will the research take place and who is the research team? The research will be led by Dr Esther Burden-Teh who is a dermatologist and researcher at the University of Nottingham. Dr Burden-Teh has led and published several projects on psoriasis in children. The research is supported by a group of advisors with expertise in psoriasis, research design, statistics and developing diagnostic criteria. How have patients and the public been involved in the research? Patients with psoriasis have emphasised the need to improve the diagnosis of psoriasis in children, especially in primary care. Patients have also made important changes to the study design such ensuring the research clinics happen alongside routine appointments and introducing a certificate of participation for all children involved. How will the research benefit patients and the NHS? The diagnostic criteria will aim to correctly identify psoriasis in at least seven out of ten children with the condition: this will be a significant improvement. The diagnostic criteria will provide health professionals with a list of skin signs to look for and questions to ask. Accurate and early diagnosis will help children receive specific treatment and monitoring for diseases such as psoriatic arthritis. Diagnostic criteria will also improve the quality of research and allow the results of studies to be combined. How will the results from the research be shared? It is important to share the results of the study with patients, parents, GPs and other health professionals. At stage 3 we will involve these groups in planning how best to share the findings. This will include conferences, journals, patient information resources and social media.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES
Health categories: SKIN