Psoriatic Arthritis Diagnosis
There are no specific clinical, laboratory or radiographic criteria for the diagnosis of psoriatic arthritis. Rather, the diagnosis should be considered in any patient with psoriasis who presents with inflammatory arthritis:
- If, as is typical, the patient is rheumatoid factor-negative, the diagnosis is relatively straightforward.
- If rheumatoid factor is present at a significant titer, the situation likely represents the coincident occurrence of psoriasis and rheumatoid arthritis.
- Given that hyperuricemia may be found in psoriasis, due to increased cell turnover, gout may also need to be considered and
- Unlike rheumatoid arthritis, both osteoarthritis and psoriatic arthritis may affect the DIP joints. Therefore, these two entities may need to be distinguished.
- The 15% of patients who present with joint disease before developing the cutaneous manifestations of psoriasis may also prove diagnostically challenging. Thus, any patient in whom the clinical presentation or pattern of disease suggests the possibility of psoriasis warrants a detailed exam of the nails, as well as for occult plaques on the scalp, behind the pinnae, in the umbilicus and in the inter-gluteal crease.
- There are no specific laboratory findings in psoriatic arthritis, although laboratory markers of inflammation may track with the activity of disease.
- Radiographically, psoriatic arthritis is a unique blend of bone destruction & proliferation. Manifestations may include erosive arthritis giving rise to the classic "pencil-in-cup" (image below)
deformity in the phalanges, osteolysis, articular ankylosis, sacroiliitis (two images below)
spondylitis (image below), enthesitis and periostitis.
1. Willkens RF, Williams HJ, Ward JR, et al: Randomized, double blind, placebo-controlled trial of low dose pulse methotrexate in psoriatic arthritis. Arthritis Rheum 27:376, 1984.
2. Espinoza LR, Zakraoni L, Espinoza CG, et al: Psoriatic arthritis: Clinical response and side effects of methotrexate therapy. J Rheumatol 19:872, 1992.
3. Gupta AK, Matteson EI, Ellis CN, et al: Cyclosporin in the treatment of psoriatic arthritis. Arch Dematol 125:507, 1989.
4. Salvarani C, Macchioni P, Olivieri I, et al: A comparison of cyclosporine, sulfasalazine, and symptomatic therapy in the treatment of psoriatic arthritis. J Rheumatol 28:2274, 2001.
5. Sarzi-Puttini P, Cazzola M, Panni B, et al: Long-term safety and efficacy of low-dose cyclosporin A in severe psoriatic arthritis. Rheumatol Int 21:234, 2002.
6. Mease PJ: Etanercept in the treatment of psoriatic arthritis and psoriasis: a randomized trial. Lancet 356:385, 2000.
7. Mease PJ: Cytokine blockers in psoriatic arthritis. Ann Rheum Dis 60:iii37, 2001.
8. Iyer S, Yamauchi P, Lowe NJ: Etanercept for severe psoriasis and psoriatic arthritis: observations on combination therapy. Br J Dermatol 146:118, 2002.
9. Cauza R, Spak M, Cauza K, Hanusch-Enserer U, Dunky A, Wagner E. Treatment of psoriatic arthritis and psoriasis vulgaris with the tumor necrosis factor inhibitor infliximab. Rheumatol Int 22(6):227, 2002.
10. Antoni C, Dechant C, Hannis-Martin Lorenz PD, Wendler J, Ogilvie A, Lueftl M, Kalden-Nemeth D, Kalden JR, Manger B. Open-label study of infliximab treatment for psoriatic arthritis: clinical and magnetic resonance imaging measurements of reduction of inflammation. Arthritis Rheum 47(5):506, 2002.
11. Mease PJ, Gladman DD, Ritchlin CT, Ruderman EM, Steinfeld SD, Choy EH, Sharp JT, Ory PA, Perdok RJ, Weinberg MA; Adalimumab Effectiveness in Psoriatic Arthritis Trial Study Group.Arthritis Rheum. Adalimumab for the treatment of patients with moderately to severely active psoriatic arthritis: results of a double-blind, randomized, placebo-controlled trial. Arthritis Rheum 52(10):3279-89, 2005.
*Images within this article are from the American College of Rheumatology Slide Collection.
