Arthritis

Question 1

What are the causes of Acute Monoarthritis

Answer 1

• Infection - Septic arthritis until proven otherwise.
• Crystal induced (Gout, Calcium Pyrophosphate),
• Reactive (could be multiple joints),
• Haemarthrosis,
• Trauma.

Question 2

What are the risk factors for septic arthritis?

Answer 2

• Previous Arthritis,
• Trauma,
• Diabetes Mellitus,
• Immunosupression,
• Bacteremia,
• Sickle Cell anamia,
• Prosthetic joint

Question 3

What is the pathogenesis of septic arthritis?

Answer 3

• Bacteria enter the joint and deposit in synovial lining either from haematogenous spread or local invasion/inoculation.
  Synovium acts as a good growth medium for bacteria

Question 4

Describe features of polyarticular septic arthritis

Answer 4

• Average of 4 joints, commonly knee, elbow, shoulder and hip predominate.
• Can often present without fever.
• Most commonly caused by strep/staph.
• Poor prognosis

Question 5

Describe features of synovial fluid in a septic arthritis

Answer 5

• Over 50k white cells per mm cubed.
• Low glucose.
• Gram staining is relatively insensitive,
• Culture will be positive,
• Always use wide bore needle as pus is viscous.

Question 6

What are the likely bugs to cause infection in healthy adults vs immunocompromised adults

Answer 6

Healthy - S. aureus, streptococcal or Neisseria gonorrhoea.
Immunocompromised - Gram negative bacteria, mycobacteria or fungi

Question 7

Explain the management of septic arthritis?

Answer 7

• Joint aspiration, Abx therapy based on culture and surgical intervention is not responding after 48 hours of treatment

Question 8

What is gout and the symptoms?

Answer 8

Gout is the deposition of monosodium urate/uric acid crystals in and around joints.
Symptoms include: Excruciating, burning pain in affected joint, commonly affects the 1st metatarsophalangeal joint. Swelling, redness and warmth in affected join. Asymmetrical distribution and mild fever/tachycardia with acute attacks

Question 9

What are the modifiable and non-modifiable risk factors for gout?

Answer 9

Non modifiable: Age, male sex, race, genetic factors, impaired renal function.
Modifiable: Obesity, alcohol consumption, high purine diet, high fructose corn syrup and certain mediations (aspirin, diuretics, cyclosporin, pyrazinamide and ethambutol and nicotinic acid)

Question 10

Explain the diagnosis of gout?

Answer 10

• Clinically via typical presentation of podagra and history of gout flares/hyperuricaemia.
• Raised serum urate between attacks,
• Synovial fluid aspiration examined under polarised light to look for gout crystals

Question 11

What are the differentials for gout?

Answer 11

• Septic arthritis,
• Psudogout which most commonly affects the knee, wrist and shoulder

Question 12

What are the goals of treatment for gout?

Answer 12

• In acute attacks the aim is to relieve pain and reduce inflammation via coldpacks and NSAIDs, colchicine or corticosteroids.
• Long term is prevention of attacks, prevent joint damage and eliminate tophi (deposit of uric acid). Use a urate lowering therapy such as allopurinol

Question 13

What are the lifestyle modifications for gout?

Answer 13

• Dietary: Reduce purine intake (avoid seafood and meat high in protein), reduce fructose containing drinks and increase skimmed milk, vegetable protein.
• Weight loss,
• Moderate exercise,
• Reduce alcohol (Especially beer)

Question 14

What is reactive arthritis?

Answer 14

• It is one of the spondyloarthropathies. It has a strong associated with HLA-B27. It occurs after an infection occurs somewhere else in the body, no organisms are in the joint. It is an immune reaction, thought to be cross reactivity between bacterial antigens and joint tissue

Question 15

What is SARA?

Answer 15

A subgroup of reactive arthritis related to a sexually acquired infection. Most commonly chlamydia trachomatis

Question 16

What are some organisms which can lead to a reactive arthritis?

Answer 16

GU infections - Chlamydia, Gonorrhoea.
Enteric infections - Salmonella, Shigella, Yersinia, Campylobacter, clostridium

Question 17

Explain the presentation of reactive arthritis

Answer 17

• Presents with triad of conjunctivitis, arthritis and urethritis.
• Onset usually 2-6 weeks after infections with a warm, swollen, tender joint often in the lower limb, dactylitis, enthesopathy. Patient can be systemically unwell with elevated inflammatory markers and malaise.

Question 18

What are the extra articular presentations of reactive arthritis

Answer 18

• Conjunctivitis, iritis, keratitis.
• Keratoderma Blennorrhagia,
• Urethritis, prostatitis, cystitis.
• Circinate balanitis,
• Stomatitis, diarrhoea,
• Occasionally aortitis

Question 19

What are the investigations for reactive arthritis?

Answer 19

• Joint aspirate to exclude sepsis.
• Swabs of urethra/cervix.
• Screen for other infections and do chlamydia serology.
• Do CRP and ESR
• Identify HLA-B27 for prognosis as they are more likely to develop chronic arthritis

Question 20

What is the management of reactive arthritis?

Answer 20

Mild - NSAID & simple analgesia.
Moderate - NSAID, joint aspirate and corticosteroid injection.
Severe/prolonged - Referal to rheumatology to consider DMARD
Treat any underlying infection elsewhere
Refer to ophthalmology for uveitis