Reactive Arthritis

Question 1

Definition, epidemiology, and pathophysiology of reactive arthritis

Answer 1

-An acute inflammatory arthritis which follows an infectious trigger (develops within 4 weeks) in a susceptible individual where the organism cannot be recovered from the joint
-Molecular mimicry hypothesis
-Population prevalence unclear
-Men affected more often than women (15:1)
-Genetic predisposition
=HLA-B27 – positive in 60% of patients
-Various organisms implicated
=Chlamydia, Shigella, Salmonella, Yersinia, Campylobacter

Question 2

Clinical features of reactive arthritis

Answer 2

-Acute onset of join pain and swelling usually affecting large joints (asymmetrical oligoarthritis of lower limbs)
-Fever, fatigue, weight loss
-Extra-articular features include:
=Conjunctivitis, Urethritis

=Waxy yellow/ brown papule skin rash on palms and soles (keratoderma blennorhagica)
=Urethritis, circinate balanitis (painless vesicles on coronal margin of prepuce)
=Enthesis
=Dactylitis, anterior uveitis
=Nail dystrophy
=CANT SEE, PEE, OR CLIMB A TREE
-Some patients progress to develop AxSpA

Question 3

Investigations in reactive arthritis

Answer 3

-Joint aspiration – key investigation
=To differentiate from crystal and septic arthritis
=Turbid fluid, many leukocytes, no growth
-Routine bloods
=ESR and CRP greatly elevated
=Neutrophilia
-Microbiology
=Stool culture and genital swabs usually negative
=Serology may reveal evidence of previous infection

Question 4

Management of reactive arthritis

Answer 4

-Rest, NSAID and analgesics
-Intra-articular steroids once infection excluded
-Immunosuppressive therapy may be required for recurrent/persistent disease (25%)
=Methotrexate, Sulfasalazine, Leflunomide
-Biologic therapy may be required for resistant or axial disease (10%)

=Symptoms rarely last more than 12 months, usually 4-6 months

Question 5

Describe enteropathic arthritis

Answer 5

-An inflammatory arthritis occurring in patients with inflammatory bowel disease
-Clinical features in keeping with AxSpA
-Thought to affect about 10% of patients with IBD
=Estimates vary widely
-Disease activity often parallels that of IBD
-Management
=Control IBD
=Methotrexate, Sulfasalazine, Leflunomide
=Avoid NSAID (can flare IBD)