Seronegative Flashcards
what is the difference between polyarthritis and oligoarthritis?
poly: >4 inflamed joints
oligo: 2-3 inflamed joints
what are the potential causes of acute polyarthritis (<6wks)?
infection, autoimmune, leukemia, crystal-induced
what infection is most likely to cause chronic polyarthritis?
HepC
seronegative spondyloarthropathies are considered ___ (acute/chronic) polyarthritis?
chronic
what are the features of seronegatives?
- RF/ANA negative
- axial arthritis (sacrum and spine)
- asymmetrical peripheral polyarthritis of the lower body
- onset <40yo
- HLA-B27 and ESR/CRP increased
- enthesitis
what is the etiology of AS?
- symmetrical sacroiliitis for all pts
- ascend from lumbar to cervical (bony fusion)
- onset 20s
- HLA-B27 variants (high in native americans)
- worse w rest
what ROM tests are done to r/i SA?
lumbar: schober test
cervical: occiput to wall distance
what is the question mark posture in SA?
decreased lumbar and cervical lordosis, increased thoracic kyphosis
what is the XR endstage of SA?
bamboo spine (due to fusion)
what are the extra-articular features of AS?
enthesitis, iritis, cardiac involvement, pulmonary fibrosis
what is the pathogenesis of AS?
HLA-B27 codes MHCI, which presents Ag to T cells, MHC binding groove binds arthritogenic peptides from gut bacteria which resembles self-Ag, leads to inflammation at enthesis
bowel diseasse usually ___(precede/follow) arthritis in enteropathic arthritis
precede
describe the skin changes in psoriatic arthritis
erythematous lesions on elbows and knees w silver lining, red spots on back, nail changes
what is a late stage finding of psoriatic arthritis?
arthritis mutilans (severe joint destruction)
what types of arthritis can lead to dactylitis?
psoriatic, reactive, gout
how does psoriatic differ from RA?
- skin and nail changes
- RF negative
- fewer joints, asymmetrical, DIP involved, scaroiliitis
- enthesitis/dactylitis
- erosion, no osteopenia
- disk-like joint regrowth in digits
what population is most affected by reactive arthritis?
males in 20s after infection
what organisms are associated with reactive arthritis?
infectious diarrhea: salmonella, yersinia, shigella, campylobacter
urogenital infection: chlamydia
what is the Sx triad of reactive arthritis?
arthritis, urethritis, conjunctivitis
DMARDs are used for (central/peripheral) arthritis?
peripheral
how long does reactive arthritis usually last?
2-3 mo
