MYOSCOPE: Bringing a visual measure of disease activity into clinical practice to help children with dermatomyositis.

Research question: To test feasibility of using a handheld tool in clinical practice for detailed imaging of nailfold blood vessels in children/young people with dermatomyositis.

To evaluate if seeing nailfold vessels in this way, and subsequent formal reporting, helps patients/parents and clinicians in shared decision-making and medicine adherence. Background: Juvenile dermatomyositis (JDM) is a rare but serious disease. It causes muscle and skin inflammation, affects blood vessels and can affect major organs.

With treatment, the disease can enter remission, but course is unpredictable and persistent disease or disease flares occur. Blood vessel abnormality (vasculopathy) is key to pathogenesis. Sub-clinical vasculopathy is thought to cause disease recurrence.

Treating optimally in early disease stages and ensuring treatment continuation until remission is vital to improve long-term outcome. Muscle inflammation often improves before skin and vascular disease.

As patients feel better, less weak, more able to do things and their illness becomes less visible, adherence to medicines that can cause weight gain, sickness and infection is more difficult.

We believe this visual tool allowing patients to see their blood vessels will help them know how active their disease is.

Our patient/parent advisory group think that this will enable children/young people to understand their disease and need for treatment.

Aims and objectives: Test feasibility (time taken/acceptability) and usefulness of nailfold capillaroscopy (NFC) in clinic, using a cost-effective handheld tool (Dinolite® CapillaryScope), alongside routine care. Methods: 40 patients will be recruited from two UK centres. During routine clinic visits, patients will have NFC in up to 8 fingers (minimum 2 fingers), taking 20-30 minutes.

An age-adjusted questionnaire will explore feelings about NFC and if perceived to be helpful.

This study is predominantly cross-sectional, but because many patients will be seen more than once over the study period, repeat assessments will be taken where possible, with a questionnaire completed by patients/parents at first and last study visit.

Study participants will be invited to participate in an individual/family interview (target 20-25 patients) to further explore impact of NFC. Options available will ensure families with digital poverty / language barriers can participate.

Clinicians will complete a questionnaire at each patient visit (1-3 per patient) to document time taken for NFC, any difficulty, and how useful NFC was.

After receiving a formal NFC report (within 1-2 weeks), clinicians will document if any further treatment changes were made. NFC will be compared to tools currently used to measure global and skin disease activity.

Timeline for delivery: At the end of this 2-year study we will know if this tool is feasible and useful in clinical practice.

Anticipated impact and dissemination: This study is nested within an established research registry network involving 16 UK paediatric rheumatology centres.

This infrastructure allows rapid training and adoption of tools beneficial for patients/parents and clinicians/researchers. If found helpful, this tool can quickly be tested/adopted by other UK centres. Handheld NFC has the potential to be used in larger-scale, longitudinal cohort studies. Results will be published and shared internationally via scientific networks, newsletters and social media.