Rheumatology Flashcards
Gout?
Monosodium urate (uric acid) crystals
Hyperuricaemia
Big toe 1st MTPJ affected, mono arthritis
Needle shaped
Pseudo gout?
Calcium pyrophosphate dihydrate crystals
Birefringence positive
Brick shaped
Rheumatoid arthritis joints?
MCP
MTP
PIP
Wrists, knees, ankles
polyarthritis
Osteoarthritis?
Cartilage worn out, bony remodelling
Gradual onset, slow progressive
Osteoarthritis joints?
DIP
PIP
CMC
Spine, knees, hips
MTP
Osteophytes at PIP joints?
Bouchard’s nodes
Osteophytes at DIP joints?
Heberden’s nodes
Bone spurs?
Osteophytes
Fibrous joints?
No space between bones, e.g. sutures in skull
Synarthroses (no movement)
Cartilaginous joints?
Bones connected by cartilage (e.g. spinal vertabrae)
Amohiarthroses - very limited movement
Synovial joints?
Space between adjoining bones (synovial cavity)
Diarthroses - free movement
Components of synovial joint
Synovium (type I collagen)
Synovial fluid (hyaluronic acid-rich viscous fluid)
Articular cartilage (type II collagen, aggrecan)
Cartilage components?
Chondrocytes
ECM (water, collagen, Proteoglycans mainly aggrecan)
Aggrecan - Proteoglycans with many chondroitin sulfate and keratin sulfate chains, interacts with hyaluronan.
Common rheumatoid arthritis extra articular features?
Fever, weight loss
Subcutaneous nodules
Subcutaneous nodules?
Central area of fibrinoid necrosis surrounded by histiocytes and peripheral layer of connective tissue.
Pathogenesis of RA?
Abnormal synovial membrane.
Neovascularisation
Lymphangiogenesis
Inflammatory cells
Dominant cytokine in RA?
Tumour necrosis factor - alpha
Blood tests for RA?
Low Hb, high platelet, high ESR, high CRP.
Antibodies in RA?
Rheumatoid factor - recognise Fc portion of IgGs.
- typically IgM.
Antibodies to citrullinated protein antigens (ACPA)
RA investigations?
X-rays
Ultrasound
MRI
Pharmacological treatments for RA?
Glucocorticoid therapy
NSAIDs
DMARDs
Methotrexate?
Inhibits dihydrofolate reductase
RA biological therapies?
- Anti-TNF
- B cell depletion
- Modulation of T cell co-stimulation
- Inhibition of IL-6 signalling
Psoriatic arthritis?
Scaly red plaques on extensor surfaces
Asymmetrical, erosions if IPJs
MCPJs NOT affected, and no rheumatoid factor.