Psoriatic Arthritis

Question 1

Epidemiology

Answer 1

Psoriasis affects 1-2% of popn. 10% of these dev arth.
Eq men and women.
Us 20-40 yo.
RF present in 10% of pts with psoriasis.
Most pts run benign course.
20% chronic.
Nail lesions often indic risk of dev arth.
Jnt symps can pre date psoriasis diag.

Question 2

Px

Answer 2

Distal, inv DIPJ
Asymm oligoarthritis
Symm polyarthitis
Spondylarthropathy
arth mutilans- bone resorp, telescoping, Shorten and ankylosis. 
Radio diffs from RA- NO juxta articular OP, DIP dis, whittling/lysis of terminal phalanges, asymm, pencil in cup deformities, ankylosis, periostitis, spondylitis. 
spinal inv
dactylitis of whole finger
tenosynovitis
enthesitis
Hyperuricaemia so risk gout. 
Skin and nail.
Jnt stiffness, pain, swell.

Question 3

Mx

Answer 3

Educ, physio, OT, surg.
mild- NSAID, then add DMARD.
Methotrexate most comm used- also helps skin. Sulfasalazine if spinal and periph jnt inv.
intra artic steroids.
Etanercept, inlfiximab and adalimumab. Pts req to have periph arth with 3+ tender and swollen jnts AND NOT resp to at least 2 stand DMARDs alone or in combin.
Surgery.
Assess tx at 12wk using PSARC measurement.

Question 4

Ix

Answer 4

XR- DIP eros, pencil in cup, mutilans.
Bloods- RF, ESR, CRP
Metabolic screen
Nail and skin
CASPAR score