Osteoarthritis and Reactive Arthritis Flashcards
Define reactive arthritis.
Sterile inflammation in joints following infection, especially urogenital and gastrointestinal infections
(not to be confused with septic inflammation)
State a urogenital infection that can cause reactive arthritis.
Chlamydia trachomatis
Give some examples of gastrointestinal infections that are associated with reactive arthritis.
Shigella
Salmonella
Campylobacter
What subset of the population does reactive arthritis tend to occur in?
It occurs mainly in young adults with a genetic predisposition and an environmental trigger
How long after the infection does the reactive arthritis tend toappear?
1-4 weeks
Describe the features of the arthritis in reactive arthritis.
It is an asymmetrical arthritis that occurs in relatively few joints (rheumatoid = symmetrical + many joints involved)
Reactive arthritis can cause enthesopathy. Which entheses are likely to get affected and what symptoms will that cause?
Achilles tendonitis
Dactylitis
Metatarsalgia (painful feet because of inflammation of the palmar fascia)
What is a very common feature of seronegative spondyloarthropathies?
Sacro-iliitis
State some extra-articular features of reactive arthritis?
Sterile conjunctivitis
Sterile urethritis
Circinate balanitis
Keratoderma blennorhagicum
What is the triad of symptoms that can be used to describereactive arthritis?
Reiter’s syndrome – joint inflammation + urethritis + conjunctivitis
Where can you get spondylitis in rheumatoid arthritis?
Only At the atlanto-axial joint.
MAIN IDEA: Rheumatoid does not involve spondylitis in general
Describe the main differences between rheumatoid arthritis and reactive arthritis.
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What is the main danger in septic arthritis?
The bacteria produce metalloproteinases that can rapidly degrade thearticular cartilage
What are the main differences between septic arthritis and reactive arthritis?
Septic arthritis has a positive synovial fluid culture
It is treated with antibiotics and may even require joint lavage
Reactive arthritis involves infection ELSEWHERE (not within the joint) and is followed by arthritis. (hence called sterile inflammation)
Describe the treatment of reactive arthritis.
It usually resolves by itself
NSAIDs and corticosteroids to control pain and inflammation.
symptomatic treatment of extra-articular manifestations
Define osteoarthritis.
Chronic slowly progressive disorder due to failure of articular cartilage that typically affects the hands (especially those involved in the pinch grip), spine and weight-bearing joints (hips and knees)
Which joints are most commonly affected in osteoarthritis?
1. Joints of the hand: DIP, PIP, first CMC 2. Spine 3. Weight-bearing joints of lower limbs esp. knees and hips First metatarsophalangeal joint (MTP)
What are the names given to the osteophytes found on the hand in osteoarthritis?
Bouchard’s Nodes – PIP
Heberden’s Nodes – DIP
What are some other associations of osteoarthritis?
Joint pain (worse with activity) Joint crepitus Joint instability Joint enlargement Joint stiffness after immobility Limitation of motion
What are some radiographic features of osteoarthritis?
Joint space narrowing
Osteophytes
Subchondral bony sclerosis
Subchondral cysts
Describe the differences between the radiographic features of rheumatoid arthritis and osteoarthritis.
Rheumatoid arthritis also has joint space narrowing but it doesn’t have subchondral sclerosis or osteophytes
There is osteopenia and there are bone erosions in rheumatoid arthritis but not in osteoarthritis
What can the osteoarthritis be caused by?
Abnormal cartilage eg due to endocrine or genetic factors
Abnormal stress on the joint eg obese patients
What is the most important component of articular cartilage?
Aggrecan
What is aggrecan made up of?
Chondroitin sulphate – glucuronic acid + N-acetyl galactosamine
Keratan sulphate – galactose + N-acetyl glucosamine
What is a proteoglycan?
Glycoproteins that contain one or more sulphated glycosaminoglycan (GAG) chains
What is special about hyaluronic acid?
It is the only non-sulphated GAG
What are the disaccharides in hyaluronic acid?
Glucuronic acid
N-acetyl glucosamine
How is osteoarthritis managed?
Physiotherapy – strengthening the muscle around the joint improves joint stability
Analgesia – paracetamol, NSAIDs, intra-articular corticosteroid injections
Joint replacement
Weight loss where appropriate
Education
Exercise
