Septic Arthritis, Crystal Arthritis and Reactive Arthritis Flashcards
1
Q
What organisms commonly cause septic arthritis?
A
- Staphylococcus aureus (most common)
- Neisseria gonorrhoea (in sexually active teenagers)
- Haemophilus influenza
- Group A streptococcus (Streptococcus pyogenes)
- Escherichia coli (E. coli)
2
Q
What are the features of gout?
A
- DIP joints most affected (base of big toe, wrists and base of thumb)
- Hot, swollen and painful joints
- Primary cause by genetic predisposition (e.g. Lesch-Nyhan syndrome)
- Secondary caused by high uric acid (MPD, leukaemia treated by chemo, thoazides, CKD)
3
Q
Diagnosis of pseudogout
A
- Joint aspirate
- No bacterial growth
- Calcium pyrophosphate crystal deposition
- Positively birefringent rhomboid crystals in aspiration
- X-ray changes
- Chondrocalcnosis is classic change seen in pseudogout (thin white line n midle of joint space)
- Other changes are similar to OA
4
Q
What are the features of reactive arthritis?
A
- Sterile synovitis following recent infection infection
- Tirgger organisms include salmonella, shigella, Yersinia, chlamydia, trachomatis
- Asymetrical lowe limb arthritis
- Usually self-limiting
5
Q
How is gout treated?
A
- NSAIDs first line
- Colchicine second line
- Corticosteroids third line
- If repeated attacks can use allopurinol (xanthine oxidase inhibitor - reduces uric acid level) - DO NOT initiate until acute attack has settled
- Lifestyle changes can help reduce risk - losing weight, staying hydrated and reducing consumption of alcohol and pruine-based foods like meat and seafood
6
Q
How is pseudogout treated?
A
- NSAIDs
- Colchicine
- Aspiration helps reduce pain and swelling
- Steroid injections
- Oral steroids
- Joint washout (arthrocentesis) is option in severe cases
7
Q
What are the features of osteoarthritis seen on X-ray?
A
- Loss of joint space
- Osteophytes
- Subchondral sclerosis
- Subchondral cysts
8
Q
What is the defintion of septic arthritis?
A
- Infection of one or more joints caused by pathogenic inoculation of microbes.
9
Q
Differential diagnosis in septic arthritis
A
- Adults
- OA
- Psoriatic arthritis
- RA
- Gout
- Pseudogout
- Haemarthrosis
- Trauma
- Bursitis
- Cellulitis
- TB (extrapulmonary)
- Children
- Transient sinovitis
- Perthes disease
- Sliped upper femoral epiphysis
- JIA
10
Q
Presentation of septic arthritis
A
- Hot, red, swollen and painful joint
- Refusing to weight bear
- Stiffness and reduced range of motion
- Systemic symptoms (i.e. fever, lethargy and sepsis)
11
Q
Management of septic arthritis
A
- Refer to orthopedics
- Joint aspirate for gram staining, crystal microscopy, culture and antibiotic sensitivities
- Empirical IV antibiotics should be given until sensitivities are known - usually continued foir 3-6 weeks
- May require surgical drainage and washout
12
Q
Complications of septic arthritis
A
- Antibiotic-associated allergic reaction
- Osteomyelitis
- Joint destruction
13
Q
Definition of gout
A
- Crystal arthropathy associated with chronically high blood uric acid levels
- Urate crystals are deposited in the joint
14
Q
Diagnosis of gout
A
- Diagnosed clinically or by aspiration of joint fluid
- Aspirate will show
- No bacterial growth
- Negatively birefringent needle shaped crystals on polarised microscopy
- Monosodium urate crystals
- Joint X-ray
- Joint space typically maintained
- Lytic lesions in the bone
- Punched out erosions
- Erosions can have sclerotic borders with overhanding edges
15
Q
Presentation of pseudogout
A
- Hot, swollen, stiff painful joint (commonly knee)
