Spondyloarthropathies

Question 1

Spondyloarthropathy

Answer 1

• Chronic systemic inflammatory disease involving SI (sacroiliac) joints, axial skeleton, peripheral joints, and extraarticular manifestations
• Includes: ankylosing spondylitis (AS), reactive arthritis, enteropathy-associated arthritis (Crohn’s and ulcerative colitis), psoriatic arthritis

Question 2

Pathogenesis of ankylosing spondylitis (AS)

Answer 2

• T cells present self HLA-B27 escapes deletion and propagates after exposure to mimicking microbial antigen
• Misfolding of B27 protein triggers Ag response and propagates Th17, causing inflammatory response
• Fluctuating inflammation causes bone erosion w/ replacement by repair tissue (osteoproliferation) resulting in syndesmophytes (bridging of bones)
• Osteitis occurs w/ ensuing effusions, enthesitis (swelling of sites where tendons/ligaments insert into bone), but not synovitis (as seen in RA)
• HLA B27 presence does not guarantee disease

Question 3

Extraarticular manifestations of spondyloarthropathies

Answer 3

• Gut, eye (acute iritis), urogenital manifestations all prototypical
• Not prototypical but occur: lung, heart, kidney, nerve involvement
• These include aortic regurgitation, apical lung pneumonitis, amyloidosis in kidneys, causa equina syndrome

Question 4

Skin manifestations of spondyloarthropathies

Answer 4

• Psoriasis (nail pitting)
• Erythema nodosa: raised inflammatory lesions
• Pyoderma gangrenosum: ulcerations
• Keratoderma blenorrhagicum-> reactive arthritis
• Pustulosis parlmaris

Question 5

Psoriatic arthritis vs RA

Answer 5

• DIPs are affected in psoriatic arthritis, and there is no osteopenia at the joints in psoriatic arthritis (there is in RA)
• MCPs/PIPs are affected in RA, not DIPs

Question 6

Radiographic features of spondyloarthropathies

Answer 6

• Pencil in cup deformity at joints (usually DIP)-> psoriatic arthritis
• Sacroiliitis: fusion of sacrum to ilium (AS usually)
• Shiny corners of joints: syndesmophytes-> bridging spondylophytes (abnormal healing from inflammation)
• Zygoapophyseal (facet joint) ankylosing
• Vertebral fractures
• Enthesitis: usually on spinal and peripheral ligaments

Question 7

Dx of spondyloarthropathies

Answer 7

• Hx of inflammatory back pain
• Enthesitis
• HLA-B27+
• Inflammatory back pain requirements: <40yo, insidious onset, improvement w/ exercise, no improvement w/ rest, pain at night

Question 8

Rx of spondyloarthropathies

Answer 8

• PT is key
• Continuous NSAIDs
• DMARDs not useful
• Usually regimen is 2+ NSAIDs w/ sulfasalazine and local steroid injections, also can use methotrexate
• TNFa Rx when needed
• Reconstructive surgery when necessary

Question 9

Spondyloarthropathies vs RA

Answer 9

• Spondyloarthropathies (HLA-B27 arthritides) differ from RA in the following ways
• High incidence of spinal joint involvement
• Usually asymmetrical lower limb involvement
• Men much more frequently affected than women
• High frequency of HLA-B27
• RF absent
• DIPs affected (PIP/MCPs affect in RA)

Question 10

Ankylosing spondylitis (AS)

Answer 10

• Inflammation starts at SI joints and progress superiorly to involve the spine
• There’s inflammation followed by abnormal healing resulting in ankylosing (fusion) of joints and ossification of paraspinal ligaments
• Position of comfort is flexion of the back
• Enthesitis, among other complications can result and cause pain at extraarticular areas

Question 11

Clinical manifestations of AS

Answer 11

• Low back pain and stiffness of >3mo, unrelieved by rest
• Limited motion of the lumbar spine (especially flexion)
• Reduced chest expansion
• Bilateral sarcoiliitis on Xray
• 40% develop peripheral arthritis mainly in hips, shoulders and knees

Question 12

Reactive arthritis

Answer 12

• Chronic recurring inflammatory disease consisting of urethritis or infectious diarrhea, conjunctivitis, arthritis, and mucocutaneous lesions
• Mainly affects lower extremity joints and is asymmetrical
• Usually self limited (lasts 2-6 mo), but recurs in 50%
• Toes involved are res and swollen, sometimes SI and spinal arthritis occurs
• Xrays can show periostitis near involved joint
• Association w/ HLA-B27: 80%

Question 13

Mucocutaneous lesions of reactive arthritis

Answer 13

• Circinate balanitis: on penis, is painless
• Painless superficial ulcers of the palate and buccal mucosa
• Keratodermia blennorrhagica: on soles of feet usually, dry hyperkeratotic rash

Question 14

Psoriatic arthritis

Answer 14

• Chronic arthritis that accompanies psoriasis in 6% of pts
• Can involve peripheral joints, SI joints, and/or spinal joints
• Psoriatic sponylitis is associated w/ HLA B27 but peripheral psoriatic arthritis is not
• Rx: methotrexate or sulfasalazine and PT. Anti-TNFa can help, so can corticosteroids

Question 15

Clinical features of psoriatic arthritis

Answer 15

• Psoriasis first, when arthritis starts it usually affects the DIPs
• Psoriatic nail involvement frequent
• Sausage (dactylitis/enthesitis) of toes or fingers
• Skin lesions of psoriasis and arthritis may wax and wane together
• Remissions more frequent than in RA
• Specific radiologic features: pencil-in-cup, whittling, periostitis and non-marginal spinal syndesmophytes