1. Gladman DD, Antoni C, Mease P, Clegg DO, Nash P. Psoriatic arthritis: epidemiology, clinical features, course, and outcome. Ann Rheum Dis. 2005;64 Suppl 2:ii14–7.
2. Mease PJ, Gladman DD, Papp KA, Khraishi MM, Thaci D, Behrens F, Northington R, Fuiman J, Bananis E, Boggs R, Alvarez D. Prevalence of rheumatologist-diagnosed psoriatic arthritis in patients with psoriasis in European/North American dermatology clinics. J Am Acad Dermatol. 2013;69:729–35.
3. Biondi Oriente C, Scarpa R, Pucino A, Oriente P. Psoriasis and psoriatic arthritis. Dermatological and rheumatological co-operative clinical report. Acta Derm Venereol Suppl (Stockh). 1989;146:69–71.
4. Scarpa R, Oriente P, Pucino A, Torella M, Vignone L, Riccio A, Biondi Oriente C. Psoriatic arthritis in psoriatic patients. Br J Rheumatol. 1984;23:246–50.
5. Shbeeb M, Uramoto KM, Gibson LE, O’Fallon WM, Gabriel SE. The epidemiology of psoriatic arthritis in Olmsted County, Minnesota, USA, 1982–1991. J Rheumatol. 2000;27:1247–50.