Rheumatology Flashcards
3 conditions causing autoimmune disease
genes
immune disregulation
environment
pathophysiology of rheumatoid arthritis
susceptibility gene: MHC-shared epitope
environmental factors: recurrent exposure to exogenous or commercial viral, bacteria or other agents (ie smoking)
all these cause epigenetic modification –> loss of tolerance
what happens in rheumatoid arthritis
chronic autoimmune disease where immune system mistakenly attacks the joints
results in chronic inflammation with joint swelling and later bone destruction
inflammatory cells lead to pannus which causes erosion to the bones or joints
in pannus, there is more synovial fluid
synovial fluid in RA is less viscous, thin and yellow, containing inflammatory cells
what other parts of the body does RA affect
inflammation can be systemic
liver blood vessels fat muscle brain bone
pathophysiology of psoriatic arthritis
genetic factors: HLA-B27
environmental factor: bacteria
what does psoriatic arthritis cause
psoriasis uveitis sacroillitis and spondlytitis peripheral joint involvement (oglioarthritis) enthesitis inflammatory bowel disease
primary site of inflammation in spondyloarthropathies
enthesis
what happens in spondyloarthropathies
mechanical injury -> vasodilation -> entheseal inflammation -> new bone formation
pathophysiology of gout
high uric acid in blood
gout is a crystal disease
pathophysiology of osteoarthritis
ageing + obesity + lifestyle choices cause inflammation of the cartilage
body is not wired to make new cartilage, but send signal to make new bones, causing bone spurs
symptoms of inflammatory arthritis
heat redness swelling pain loss of function
things to look out for when patient complains of joint pain
where is the pain - to ensure it is from the joint and not muscle
articular or non-articular - joint line, ROM
is the pain inflammatory - swelling, redness, warmth
how many joints are involved - monoarticular, oligoarticular, polyarticular
how bad is the pain - how is function affected
patterns of joint involvement
osteoarthritis
- neck
- LS spine
- hip
- knee
- foot: 1st MTP
- hand: 1st CMC; DIP, PIP
rheumatoid arthritis
- proximal joints of digits symmetric
reiter’s syndrome
- lower extremity: foot; knee; ankle; hip
- LS spine
- SI joints asymmetric
ankylosing spondylitis
- spine (entire)
- SI joints
- hip
- shoulder
psoriatic arthritis
- hands and feet (distal)
- LS spine
- SI joint asymmetric
clinical features of RA
involvement of both large and small joints, sparing DIPJs
temporomandibular joints and cervical spine may be involved (atlanto-axial subluxation)
common clinical features of all spondyloarthropathies
- axial or oligoarticular involvement
- enthesitis
- extra-articular involvement - eye, skin, genitourinary tract
- HLA-B27+
- rheumatoid factor negative
