Psoriatic Arthritis


Examine this patient's hands.



· Cutaneous psoriasis with itching in a filth of the patients.

· Joint pain, joint stiffness worse in the morning.


Distal interphalangeal joint involvement.

Proceed as follows:

· Tell the examiner that you would like to:

-Examine the nails, looking for pitting, onycholysis, discoloration, thickening

(nails are involved in 80% of patients with psoriatic arthritis).

-Look for psoriatic plaques in the extensor aspects of elbows, scalp, sub-mammary region, umbilicus and natal cleft; describe these

as reddish plaques with well-defined edges and silvery white scales.

· Comment on the fingers, which are sausage shaped due to tenosynovitis.


This patient has nail pitting, psoriatic plaques and distal interphalangeal arthropathy (lesion) due to psoriasis (aetiology) and has

good hand function (functional status).


What are the patterns of joint involvement seen in psoriasis?

The patterns include (Acta Derm Venereol 1961; 41: 396403):

· Asymmetrical terminal joint involvement.

· Symmetrical joint involvement as seen in rheumatoid arthritis.

· Sacroiliitis: this differs from ankylosing spondylitis, most notably in that the syndesmophytes tend to arise from the lateral and

anterior surfaces of the vertebral bodies and not at the margins of the bodies.

· Arthritis mutilans - complicated by the 'telescoping' of digits.

What are the radiological features of psoriatic arthritis?

· 'Fluffy' periostitis.

· Destruction of small joints.

· 'Pencil and cup' appearance, osteolysis and ankylosis in arthritis mutilans.

· Non-marginal syndesmophytes in spondylitis (Q J Med 1977; 46: 411).

What is the prognosis?

Deforming and erosive arthritis is present in 40% of cases, and 11% of patients are disabled by their arthritis (Lancet 1988; ii: 375).