Reactive Arthritis

Question 1

Define:

Answer 1

• Characterised by a sterile arthritis occurring after an extra-articular infection (commonly GI or urogenital).
Typically affects lower limbs 1-4 weeks after urethritis or dysentery

Seronegative arthropathies

Question 2

What is Reiter’s Syndrome triad:

Answer 2

o Reactive arthritis
o Urethritis
o Conjunctivitis

Question 3

Aetiology/risk factors:

Answer 3

o	GI
	Salmonella
	Shigella 
	Yersinia
	Campylobacter

Urogenital
 Chlamydia trachomatis (60%)
 Ureaplasma species

It is thought that initial activation of the immune system by a microbial antigen is followed by an autoimmune reaction that involves the skin, eyes and joints

HLA-B27 allele is identified in 70-80% of patients

Question 4

Epidemiology:

Answer 4

• 20 x more common in MALES
• Age of onset: 20-40 yrs
• Seen in 2% of patients with non-specific urethritis

Question 5

Symptoms:

Answer 5

• Symptoms can develop 3-30 days after infection
• Burning or stinging when passing urine (due to urethritis)
• Arthritis
• Low back pain (due to sacroiliitis)
• Painful heels (due to enthesitis and plantar fasciitis)
• Conjunctivitis

Question 6

Signs:

Answer 6

o Asymmetrical oligoarthritis

• Often affects the lower extremities
• Sausage-shaped digits

Signs of Conjunctivitis (Anterior uveitis - painful red eye)
• Circinate Balanitis (Scaling red patches on the glans + Painless)
• Keratoderma Blenorrhagica (Brownish-red macules Found on the SOLES and PALMS)

o Nail dystrophy
o Hyperkeratosis
o Onycholysis
o Mouth ulcers

Question 7

Investigations:

Answer 7

o FBC
o High ESR and CRP
o HLA-B27 testing

Stool or Urethral Swabs and Cultures
o May be negative by the time the arthritis develops (because the arthritis occurs post-infection)

Urine
o Screen for Chlamydia trachomatis

Plain X-Rays
o Useful in chronic cases
o Erosions seen at the entheses (insertion of tendons into bone)

Joint Aspiration
o To exclude septic or crystal arthritis