Inflammatory Arthritis Flashcards
What are the clinical signs of inflammatory arthritis?
General stiffness Lameness Pyrexia, lethargy, inappetence Multiple painful swollen joints Stilted posture Arthralgia
What diagnostic tests should be done if arthralgia is found on clinical exam?
Cytology of joint fluid
What does a positive culture of joint fluid cytology indicate?
Septic arthritis
What further tests should be done if cytology of joint fluid is sterile?
CBC biochem
US
Thoracic radiographs
Echocardiography
How is septic and immune-mediated arthrocentesis differentiated?
Septic - degenerative neutrophils
IM - non-degenerative neutrophils
What diagnostic test and result in arthralgia indicated chronicity?
Radiographs
Normal –> Acute
Erosion of cartilage and subchondral bone –> Chronic
How is inflammatory arthritis categorised?
First broken down into infective and non-infective.
Non-infective is further broken down into erosive and non-erosive
Describe normal joint fluid
Clear, pale yellow
Transparent
V viscous
Low WBCs
Describe DJD synovial fluid
Yellow Transparent Viscous May clot spontaneously Low WBCs
Describe immune mediated arthritis synovial fluid…
Yellow, may be blood tinged Transparent or opaque Watery Spontaneously clots High protein High WBCs
Describe bacterial infective arthritis synovial fluid…
Yellow, may be blood tinged Opaque Watery Clots spontaneously V high protein High WBCs
What can cause septic arthritis?
Haematogenous e.g. foals umbilicus
Trauma
Iatrogenic e.g. IA injections
How is septic arthritis treated in small animals?
Amoxiclav
How is septic arthritis treated in horses?
Penicillin, gentamicin IA/IM
Thorough lavage, arthroscopy
Sample joint fluid q48hrs
Oral ABs
Outline the pathogenesis of immune-mediated polyarthritis…
Ag/ab complexes deposited on synvoium > synoviocytes activated > release chrondrodestructive collagenases > osteoclasts cause bone resorption and subchondral cysts > Pannus formation
How does the immune system fail during immune-mediated polyarthritis?
Fails to recognise self > autoaggressive cells proliferate
What risk factors are there for developing autoimmune disease?
Inherited Certain infections Bacterial endocarditis Discospondylitis Immune mediated bowel disease Neoplasia Chronic hepatitis
Out the Igs involved in types 1-4 hypersensitivity reactions
- IgE - Mast cells basophils
- IgG or IgM
- IgG or IgM
- Intracellular
Which type of hypersensitivity is immune mediated arthritis?
Type III
Define monoarticular, pauciarticular and polyarticular
Monoarticular - affecting 1 joint
Pauciarticular - affecting 2-5 joints
Polyarticular - affecting 6+ joints
What should be included in a PE in an arthritic patient?
Observe walking
Full clinical exam
Palpation and manipulation
ROM, pain, heat, swelling and crepitus
What diagnostic tests are used in a patient with polyarthropathy?
Arthrocentesis
Joint radiography
Synovial biopsy
What can cause non-erosive polyarthritis?
Systemic lupus erthematosus Lyme disease Iatrogenic Calicivirus Steroid-responsive meningitis-arteritis IBD Vaccine induced
Outline the pathogenesis of erosive polyarthritis
Chronic synovitis > profilerative granulation tissue (pannus) > invades articular cartilage and subchondral bone > protreases and collagenases produced > further joint destruction
What other disease procress does erosive arthritis cause changes similar too?
Septic arthritis
Give 3 examples of erosive joint disease
Rheumatoid arthritis
Periosteal proliferative polyarthritis in cats
Polyarthritis of greyhounds (Felty’s syndrome)
What are the clinical signs of Felty’s syndrome?
Rheumatoid arthritis
Splenomegaly
Neutropenia
What radiographic changes occur in erosive arthritis?
Subchondral bone erosion
Destructive symmetrical multijoint arthropathy
Collapse of joint spaces
Joint deformity of subluxation
Periarticular new bone formation
Calcification of periarticular soft tissues
How can rhumatoid arthritis and SLE be differentiated in diagnosis/
Serology
RA +ve for rheumatoid factor
SLE - anti-nuclear antibody test
What are the general principles of therapy to treat inflammatory arthritis?
Removal inciting factor
Suppress immune respoinse
Analgesia
Reduce joint stress
What drugs can be used to treat inflammatory arthritis?
Pred
Cyclophosphamide
Anti TNFa, IL-1 blockers
Leflunomide (antirheumatic drugs)
When might surgery be indicated in inflammatory arthritis?
Persistent inflammation can cause subluxation
Outline the pathogenesis of gout in reptiles
Renal damage –> decreased excretion of urate –> urate crystal deposition –> inflam reaction
How is gout treated in reptiles?
Fluid therapy
