Reactive arthritis

Question 1

What is reactive arthritis? What are the associations, both genetic and infectious?

Answer 1

Acute, non-purulent arthritis complicating an infection elsewhere in the body

• classically either following enteric or venereal infection

HLA-B27 association varies with infectious aetiology; associated with worse outcome

• Little association with campylobacter; lower prevalence with salmonella, rarely can occur post c difficile
• Higher rates of B27 +ve with shigella, yersinia, chlamydia.

Often the first manifestation of HIV infection, remitting with disease progression

• In Western white people, it tends to flare as AIDS advances

Bacteria are classically gram negatives with lipopolysaccharide component to the cell wall

• Chlamydia trachomatis much more common than pneumonia, but pneumonia may occur
• Ocular serovars of trachomatis much more arthritogenic

Question 2

How does reactive arthritis present? What’s the characteristic rash associated with it?

Answer 2

Spectrum from isolated transient monoarthritis to severe, multisystem disease

• Usually associated with an infection in the prior 1-4 weeks
• May progress to frank ankylosing spondylitis

Symptoms

• constitutional symptoms common
• musculoskeletal is usually acute onset
• asymmetric additive arthritis, with new joints involved over days to weeks. Often painful with tensef effusions not uncommon
• typically persisting for 3-5 months but may be more chronic
• lower extremity more often but can involve wrists and fingers
• dactylitis a distinctive feature of peripheral spondyloarthrtides
• tendinitis and fasciitis are also characteristic
• spinal and lower back pain common
• urogenital may occur throughout the course, either primary infective or reactive
• • urethritis in males, cervicitis or salpingitis in females
• • occurs in both venereal and enteric

- ocular is common

• • ranges from asymptomatic conjunctivitis to aggressive anterior uveitis refractory to treatment

- mucocutaneous also common

• oral ulcers are typically superficial and often asymptomatic
• keratoderma blenorrhagica is characteristic. Palms or soles most commonly. Vesicles or pustules that become hyperkeratotic, forming a crust before disappearing. May be extensive in HIV, dominating the picture
• circinate balanitis is similar but on the glans of the penis
• nail changes common: onycholysis, yellow discolouration, hyperkeratosis

Question 4

What are the laboratory and xray findings in reactive arthritis? How is it diagnosed?

Answer 4

Laboratory findings are non-specific

• • HLA-B27 has prognostic value so should be sent
• • acute phase reactants often markedly elevated in acute phase
• • synovial fluid inflammatory
• • serology is non-specific and not useful
• • chlamydia first void urine PCR has high sensitivity in the acute phase but not chronic

Radiographic

• • may have nothing early, may have juxtaarticular osteoporosis
• • longstanding disease shares features with psoriatic arthritis: marginal erosions and loss of joint space
• • periostitis with reactive new bone formation is characteristic of spondyloarthritides. plantar fascia spurs common
• • sacroiliitis and spondylitis found late
• • sacroiliitis more asymmetric than in ankylosing spondylitis
• • spondylitis random rather than ascending like in AS
• • syndesmophytes look different to AS: non-marginal, arising from the middle of vertebrae, fusion uncommon

Diagnosis

• • clinical diagnosis, consider in any acute, inflammatory, asymmetric arthritis/tendinitis
• look for distribution of manifestations to differentiate
• differentiate from disseminated gonococcal disease: gon associated with vesicular lesions and tends to have equal upper/lower, sparing axial
• psoriatic arthritis is primarily upper extremity and doesn’t have mouth ulcers, urethritis, or bowel symptoms

Question 5

How is reactive arthritis treated?

Answer 5

Most benefit to some degree from high dose NSAIDs, indomethacin preferred

Prompt antibiotics for acute chlamydial urethritis or enteritis may prevent development

• most trials of antibiotics after arthritis onset show no benefit
• 6 months of rifampicin + azithromycin or rifampicin + doxycycline benefits chronic reactive arthritis due to chlamydia

DMARDs

• sulfasalazine may be beneficial
• azathioprine and methotrexate never studied but may be of benefit
• no formal studies of anti-TNFa
• intralesional corticosteroids can help enthesitis
• uveitis can require aggressive treatment, but usually responds to topical steroids
• skin lesions usually only need topical treatment. In HIV respond to ART