1 The Dermatology Centre, Salford Royal NHS Foundation Trust, Stott Lane, Salford M6 8HD, Greater Manchester, UK.
2 Centre for Dermatology Research, MAHSC and NIHR Manchester Biomedical Research Centre, University of Manchester, Stopford Building, Oxford Road, Manchester M13 9PG, UK.
3 Alan Lyell Centre for Dermatology, Queen Elizabeth University Hospital, 1345 Govan Road, Glasgow G51 4TF, UK.