Reactive arthritis Flashcards
Define reactive arthritis
Characterised by a sterile arthritis occurring after an extra-articular infection (commonly GI or urogenital).
Reiter’s Syndrome is defined as a TRIAD of:
Reactive arthritis
Urethritis
Conjunctivitis
Explain the aetiology/risk factors for reactive arthritis
Associated with infections:
GI - Salmonella, Shigella, Yersinia, Campylobacter
Urogenital - Chlamydia trachomatis (60%)
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
Summarise the epidemiology of reactive arthritis
20 x more common in MALES
Age of onset: 20-40 yrs
Seen in 2% of patients with non-specific urethritis
Recognise the presenting symptoms of reactive arthritis
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
Recognise the signs of reactive arthritis on physical examination
Signs of Arthritis - Asymmetrical oligoarthritis
Often affects the lower extremities
Sausage-shaped digits
Signs of Conjunctivitis - Anterior uveitis- painful red eye
Oral Ulceration
Circinate Balanitis - Scaling red patches on the glans
Keratoderma Blenorrhagica - Brownish-red macules
Vesicopustules
Yellowish-brown scales
Found on the SOLES and PALMS
Others
Nail dystrophy
Hyperkeratosis
Onycholysis
Identify appropriate investigations for reactive arthritis
Bloods
FBC
High ESR and CRP
HLA-B27 testing
Stool or Urethral Swabs and Cultures - May be negative by the time the arthritis develops (because the arthritis occurs post-infection)
Urine - Screen for Chlamydia trachomatis
Plain X-Rays - Useful in chronic cases
Erosions seen at the entheses (insertion of tendons into bone)
Joint Aspiration - To exclude septic or crystal arthritis
