Psoriasis/Psoriatic Arthritis

Question 1

Epidemiology of Psoriatic Arthritis

Answer 1

Psoriatic arthritis develops in 5-40% of those with psoriasis.

Psoriasis affects 1-5% of the world’s population.

Peak onset at ages 16 to 22 and at ages 57 to 60 but can strike at any age.

Question 2

Aetiology of Psoriasis

Answer 2

Genetic-environmental interaction for psoriasis - triggers include: injury, sunburn, HIV, strep, stress, drugs, alcohol, smoking, obesity
immune system stimulation of keratenocytes

Question 3

Pathogensis

Answer 3

not understood,Psoriasis is hyperproliferation of epidermal keratinocytes combined with inflammation of the epidermis and dermis.
-ve RF
substantial leucocyte recruitment to dermis

Question 4

Natural History

Answer 4

Arthritic remissions tend to be more frequent, rapid, and complete than in RA, but progression to chronic arthritis and crippling may occur.
remissions of 5 years ( 5%)

Question 5

Manefestations

Answer 5

Psoriasis:
lesions asymptomatic or pruritic and localized on the scalp, extensor surfaces of the elbows and knees, sacrum, buttocks, and genitals.
The nails, eyebrows, axillae, umbilicus, and perianal region may also be affected. The disease can be widespread.

Psoriatic Arthritis:
(DIP) joints of fingers and toes are especially affected.

Asymmetric involvement of joints, including SIJ and spine, is common. Joint and skin symptoms may lessen or worsen simultaneously. Back pain may be present. Asymmetric syndesmophytes of the spine.

Arthritis may manifest before skin lesions.

Question 6

symptoms

Answer 6

less extra-articular s/s than RA but ocular symptoms may occur.

Question 7

signs

Answer 7

discrete, erythematous plaques covered with thick, silvery, shiny scales. Lesions appear gradually and remit and recur spontaneously or with the appearance and resolution of triggers.
sausage digits
most commonly scalp, knees/elbows/sacrum/buttocks and genitals

Question 8

Complications

Answer 8

Inflammation of the fingers, toes, or both may lead to sausage-shaped deformities. There may be arthritis mutilans (destruction of multiple hand joints with telescoping of the digits).
mitral valve prolaspe
increased risk of CVHD

Question 9

Prognosis

Answer 9

7% require musculoskeletal surgery for joint deformity. Severe disease in 20%
self image/