RT Book, Section A1 Murtagh, John A1 Murtagh, Clare SR Print(0) ID 1208725495 T1 Psoriasis T2 John Murtagh’s General Practice Companion Handbook, 8th Edition YR 2022 FD 2022 PB McGraw-Hill Education (Australia) Pty Ltd PP Sydney, Australia SN 9781743768266 LK murtagh.mhmedical.com/content.aspx?aid=1208725495 RD 2024/10/09 AB A chronic, immune-mediated skin disorder of unknown aetiology which affects 2–4% of the population. It appears most often between the ages of 10 and 30 yrs, although its onset can occur any time from infancy to old age.