Reactive arthritis

Question 1

Define reactive arthritis.

Answer 1

Reactive arthritis (ReA) is an inflammatory arthritis that occurs after exposure to certain gastrointestinal and genitourinary infections. It is part of the inflammatory spondyloarthropathies group.

Question 2

What is the triad of reactive arthritis?

Answer 2

Conjunctivitis

Urethritis (non-gonococcal)

Arthritis

Question 3

What is the aetiology of reactive arthritis?

Answer 3

Usually either sexually transmitted or associated with bacillary dysentery

Question 4

What are the rates of ReA post Chlamydia vs post-dysentery?

Answer 4

The attack rate of ReA after:

• C trachomatis infection ranges from about 4% to 8%
• Dysentery ReA ranges from 1.5% to about 30%

Question 5

What bacteria contribute to ReA?

Answer 5

• Chlamydia - C trachomatis and C pneumoniae
• Campylobacter jejuni
• Salmonella enteritidis
• Shigella
• Yersinia

Question 6

What are the clinical features of reactive arthritis?

Answer 6

• Acute or gradual onset
• Widespread or monoarticular - usually large joints
• Ophthalmic symptoms and urethritis may occur separately
• Plantar fasciitis
• Achilles tendinitis
• Sacroiliitis
• Raised ESR
• Negative RF (seronegative)

Question 7

What investigations should be done in ReA?

Answer 7

Bloods:

• ESR, CRP - elevated
• RF, ANA, urogenital and stool cultures - all negative, unless tested very early in onset of infection
• NAAT - may be positive for Chlamydia trachomatis or Neisseria gonorrhoeae

Imaging/invasive:

• Plain XR - look for asymmetrical sacroiliitis
• Arthrocentesis - rule out crystal-induced arthritis such as gout

Other:

• HLA-B27 - positive or negative
• MRI
• US

Question 8

What is the management of ReA?

Answer 8

• NSAIDs
• Corticosteroids - may be used in acute flare or if symptoms are unresponsive to NSAIDs. Good for peripheral joint involevement
• DMARDs - used to prevent radiographic joint destruction

Other:

• Abx for urethritis - but difficult to eliminate
• Rest - to ease chronic joint symptoms
• Physiotherapy

Question 9

What is the prognosis with ReA?

Answer 9

Approximately 50% of patients can expect symptoms to resolve within the first 6 months

30% to 50% of patients will develop chronic ReA