Seronegative Spondyloarthropathy Flashcards
seronegative spondyloarthropathies - defined
*a group of rheumatic diseases that are seronegative and associated with HLA-B27, including:
-Psoriatic arthritis (PsA)
-Ankylosing spondylitis (AS)
-Inflammatory Bowel Disease-related arthritis
-Reactive arthritis
-Juvenile onset spondyloarthritis
note - seronegative = RF (rheumatoid factor) is negative
seronegative spondyloarthropathies - shared features
*strongly associated with HLA-B27
*clinical features:
-inflammatory axial involvement (back, SI joints)
-peripheral arthritis (asymmetric lower extremity)
-dactylitis (sausage digit)
-enthesitis (inflammation of tendon insertion sites)
-inflammatory eye and bowel disease
recall: inflammatory = morning stiffness > 1 hour, improves with activity and worsens with rest
HLA-B27 overview
*lies in MHC region on short arm of chromosome 6
*associated with the seronegative spondyloarthropathies (ankylosing spondylitis, reactive arthritis, psoriatic arthritis)
*NOT diagnostic
*prognostic marker for disease: earlier onset, more severe disease, sacroiliitis, uveitis
seronegative spondyloarthropathies - inflammatory components
*slightly different inflammatory cytokines from RA
*IL-12, 17, 23
*creates unique disease-modifying drug targets
ankylosing spondylitis - epidemiology
*peak age of onset between 20-30 years
*9:1 male predominance
*more common in Caucasians
*delay to diagnosis: usually 5-7 years after disease onset
clasically: young white male presenting with chronic low back pain
ankylosing spondylitis - symptoms
- inflammatory back pain: improves with exercise, worsens with rest, worst at night, age of onset MUST BE < 40
- SI joint arthritis, symmetric involvement
- enthesitis
- peripheral arthritis (typically asymmetric)
ankylosing spondylitis - extra-axial manifestations
*eye: acute anterior uveitis
*CV: aortic regurgitation, aortitis
*pulmonary: reduced TLC (restrictive lung disease), apical fibrosis
*renal: IgA nephropathy, amyloidosis
*GI: asymptomatic ileal/colonic mucosal ulceration
ankylosing spondylitis - physical exam finding
*Schober test:
-mark at 0 and 10cm from lumbosacral (LS) junction
-ask patient to forward flex as far as possible
-flexion should increase more than 5 cm (> 15cm)
ankylosing spondylitis - radiology findings
*AP pelvis: sacroiliitis, SI joint fusion
*spinal radiography:
-squaring of vertebral bodies
-bridging syndesmophytes
-calcification of anterior spinal ligament
-bamboo spine (see image)
*MRI: more sensitive (early changes), bone marrow edema
ankylosing spondylitis - treatment
- NSAIDs = first line (improves back pain or stiffness in 70-80% of patients)
- methotrexate + sulfasalazine - great for PERIPHERAL disease, not as good for axial sx
- TNF inhibitors - great for axial symptoms
- newer medications
psoriatic arthritis (PsA) - overview / epidemiology
*inflammatory arthritis associated with psoriasis (morning stiffness > 1 hour, improves with activity, worsens with rest)
*affects men and women equally
*prevalence in patients with psoriasis = 15-20%
*majority of the time, psoriasis precedes arthritis, but can occur concurrently or in reverse order
*if severe and sudden, check HIV status
psoriatic arthritis (PsA) - symptoms
- inflammatory arthritis: distal arthritis (DIP and PIP joints)
- dactylitis (sausage digits)
- enthesitis
- nail lesions: pitting, plaques, nail plate crumbling
psoriatic arthritis (PsA) - radiology findings
*pencil-in-cup deformity
*periostitis (new bone formation)
*soft tissue swelling
psoriatic arthritis (PsA) - treatment
- methotrexate (good for peripheral joint pain + skin disease)
- anti-TNF agents (great for axial + peripheral symptoms + skin disease)
- other medications (IL12/IL23, IL17, IL23, and Jak inhibitors)
reactive arthritis - overview
*commonly follows a preceding infection:
-enteric infections (salmonella, shigella, yersinia, campylobacter, C diff)
-GU infections (Chlamydia trachomatis)
*symptoms occur 1-3 weeks after infection: can’t see, can’t pee, can’t climb a tree = conjunctivitis + urethritis + arthritis
*previously called Reiter’s Syndrome
reactive arthritis - symptoms
can’t see, can’t pee, can’t climb a tree = conjunctivitis + urethritis + arthritis
- articular manifestations:
-arthritis = asymmetric, lower extremity
-enthesitis, dactylitis - extraarticular:
-conjunctivitis, urethritis
-mucosal lesions
-cutaneous eruptions (keratoderma blennorrhagica - see image)
-genital lesions (circinate balanitis)
