[1] So Gen Hosp, Dept Dermatol, Glasgow G51 4TF, Lanark, Scotland
[2] Thomas Jefferson Univ, Jefferson Med Coll, Dept Dermatol & Cutaneous Biol, Epithellal Genet Grp, Philadelphia, PA 19107 USA
[3] Craigavon Area Hosp, Dept Dermatol, Craigavon, North Ireland
[4] Royal Victoria Hosp, Dept Dermatol, Belfast BT12 6BA, Antrim, North Ireland