[1] Royal Liverpool & Broadgreen Univ Hosp NHS Trust, Dept Dermatol, Liverpool, Merseyside, England
[2] St Helens & Knowsley NHS Trust, Dept Dermatol, Prescot, Merseyside, England
[3] Royal Liverpool & Broadgreen Univ Hosp NHS Trust, Dept Infect Dis, Liverpool, Merseyside, England
[4] St Helens & Knowsley NHS Trust, Dept Pathol, Prescot, Merseyside, England
[5] Univ Liverpool, Dept Mol & Clin Pharmacol, Liverpool L69 3BX, Merseyside, England