RT Book, Section A1 Hellmann, David B. A1 Imboden Jr., John B. A2 Papadakis, Maxine A. A2 McPhee, Stephen J. A2 Rabow, Michael W. SR Print(0) ID 1174855585 T1 Psoriatic Arthritis T2 Current Medical Diagnosis and Treatment 2020 YR 2020 FD 2020 PB McGraw-Hill Education PP New York, NY SN 9781260455281 LK accessmedicine.mhmedical.com/content.aspx?aid=1174855585 RD 2021/01/22 AB ESSENTIALS OF DIAGNOSISPsoriasis precedes arthritis in 80% of cases.Arthritis: usually asymmetric, with “sausage” appearance of fingers and toes; polyarthritis that resembles rheumatoid arthritis also occurs.Sacroiliac joint involvement common.Radiographic findings: osteolysis; pencil-in-cup deformity; relative lack of osteoporosis; bony ankylosis; asymmetric sacroiliitis and atypical syndesmophytes.