[1] Sheffield Childrens NHS Fdn Trust, Dept Paediat Rheumatol, Sheffield, S Yorkshire, England
[2] Alder Hey Childrens NHS Fdn Trust, Dept Paediat Rheumatol, Liverpool, Merseyside, England
[3] Univ Nottingham Hosp, NHS Trust, Dept Dermatol, Nottingham NG7 2UH, England
[4] Newcastle Upon Tyne Hosp, NHS Fdn Trust, Dept Dermatol, Newcastle Upon Tyne, Tyne & Wear, England
[5] Inst Cellular Med, Musculoskeletal Res Grp, Newcastle Upon Tyne, Tyne & Wear, England