Reactive Arthritis

Question 1

Define reactive arthritis

Answer 1

Sterile arthritis occurring after GI or GU infection

Reiter’s syndrome is a triad of reactive arthritis, urethritis and conjunctivitis (can’t see, can’t pee, can’t climb a tree)

Question 2

What are the causes/risk factors of reactive arthritis?

Answer 2

Microbial antigen -> activation of immune system -> autoimmune
reaction in skin, eyes and joints
Associated with HLA-B27 (?molecular mimicry)
GI infections
• Shigella
• Salmonella
• Yersinia
• Campylobacter
GU infections
• Chlamydia trochomatis (60%)

Question 3

What are the symptoms of reactive arthritis?

Answer 3

Symptoms develop within 30 days of GI or GU infection

Asymmetrical oligoarthritis affecting knees, ankles, feet
• Painful, swollen, red, stiff joints

Urethritis
• Dysuria

Sacroiliitis
• Back pain

Enthesitis e.g. plantar fasciitis, Achilles tendonitis
• Painful heels

Anterior uveitis
• Painful red eye

Other
• Fever

Question 4

What are the signs of reactive arthritis?

Answer 4

• Conjunctivitis – red eyes
• Painless oral ulcers
• Circinate balanitis – painless ulcers, plaque-like lesions on shaft or glans of penis
• Keratoderma blenorrhagica – red plaques and pustules on palms and soles
• Hyperkeratosis
• Onycholysis

Question 5

What investigations are carried out for reactive arthritis?

Answer 5

• ESR/ CRP - elevated
• Antibody Serology - negative; seronegative arthropathy.
• UGT and Stool Samples - negative unless patients are tested very early after onset of infection.
• X-Ray - may show enthesitis with periosteal reaction and a bamboo-spine in Sacroiliitis.
• Joint Aspirations - to exclude gout and septic arthritis