10- Psoriatic Arthritis Flashcards
Give me some general info on Psoriatic Arthritis
- its a common skin disorder that is associated with erosive and at times deforming arthropathy (disease of a joint)
- accounts for approx 15% of patient suffering from arthritic conditions resulting from synovitis
- predominant distribution is peripheral joints of hand and feet but may also effect SI joints and spine.
- great similarities to RH except that it doesn’t have the Rhematoid factor
- cant really distinguish it from Reiters syndrome.
What is the clinical features of Psoriatic Arthitis
pg 22 of reader
1051 of txt
− 20-50 yrs, no sex predilection
− Arthritis develops within 5 years of skin condition − 80% with nail changes develop arthritis in DIPs
− “Sausage digit”, tenosynovitis
− Low back pain, may radiate
− Lab findings: ESR up, negative to Rhematoid factor
-The presence of HLA-b27 antigen seems to correlate with the susceptibility of developing PA
− 75% with SI involved, +HLA-B27
− 30% w/peripheral changes +HLA-B27
− 8% HLA-B27 in normal pop.
-early signs are DIP joint redness, swelling and pain or entire digit might be swollen (sausage)
What are some of the pathologic features of PA
1051
- pannus(Pannus is defined as thickening synovial tissue) formation, fibrosis, erosion
- normal bone density
- enthesophytes (abnormal bony projections at the attachment of a tendon or ligament.) form at the calcareous, foot and hand
- lack of hyperaemia, normal bone mineralization adjacent to involved joints
What are the radiographic features of PA
22
- Soft tissue swelling- may be earliest and only radiographic sign
- Bone density-Noramal bone density despite the destructive changes, it is a useful differential feature from RH
- Marginal Erosions- rate bite erosions
- Fluffy, hazy periostitis- The new bone forming in periosteum is fluffy
- Ankylosis- abnormal adhesion of the bones of a joint–>
Anatomy . the union or consolidation of two or more bones or other hard tissues into one.
check out pg 1053- shows that just 2 fingers are affected showing asymmetry-diagnostic for psoriases
Targeted sites of Involvment:
Hands
pg 1052 txt
22 reader
− Affects DIPs and PIPs earliest
− Uncommon for MCP, wrist involvement
− 3 Joints affected in a single ray (Ray pattern)
− Asymmetric distribution
− Joint “widening”, erosion, fibrous deposition
− Marginal erosions with adjacent periostitis = “mouse
ears”
− Whittling of phalanx, erosion into articular surface -
“pencil in cup”
− Severe deformity, arthritis mutilans − Can see acro-osteolysis
− 15% get intraarticular ankylosis
− DDX: RA, erosive arthritis
targeted sites of involvement
Feet
pg 1053
− Findings in feet parallel the hands
− Great toe, IP joint m.c. affected
− Osteolysis metatarsal heads, distal tufts − Achilles, plantar insertions get erosions
Targeted sites of involvement
Sacroiliac Joint
23
1054 txt
− 30-50% of patients have SI involvement
− Bilateral, asymmetric mc pattern
− Erosions, hazy joint surface, subchondral sclerosis − SI narrowing, ankylosis uncommon
− Enthesopathy at the crests, tuberosities
targeted sites of involvement
Spine
23
1054
− 60% w/psoriatic arthritis get spondylitis (Spondylitis is an inflammation of the vertebra. It is a form of spondylopathy)
− Coarse, asymmetric non-marginal (para)syndesmophyte-A syndesmophyte is a bony growth originating inside a ligament, commonly seen in the ligaments of the spine, specifically the ligaments in the intervertebral joints leading to fusion of vertebrae.
− Seen T11-L3, thick or thin
− Unilateral, asymmetric, alternating sides
− In 35-75% of patients the cervical spine is involved
− See narrowing/fusion of facets, dislocations, syndesmophytes (A syndesmophyte is a bony growth originating inside a ligament, commonly seen in the ligaments of the spine, specifically the ligaments in the intervertebral joints leading to fusion of vertebrae)
− 45% of patients get C1-C2 instability, erosions/sclerosis of dens
