Reactive arthritis (ReA) is an inflammatory arthritis that occurs after exposure to certain gastrointestinal and genitourinary infections. Patients with ReA may give a history of an antecedent infection 1 to 4 weeks before onset.

The classical triad of post-infectious arthritis, non-gonococcal urethritis, and conjunctivitis is frequently described but found only in a minority of cases and not required for diagnosis

• 'Can't see, pee or climb a tree’

Aetiology:

Strong association with HLA-B27

Subdivided into:

• Post enteric - Following complylobacter, Salmonella and Shigella
• Post venereal - Following chlamydia or HIV infection

Bacterial DNA and RNA gets into the synovial tissue of patients - stimulates inflammatory arthritis as a result

Epidemiology

• post-STI form much more common in men (e.g. 10:1)
• post-dysenteric form equal sex incidence

Risk factors:

• Male
• HLA-B27
• Preceding chlamydial or GI infection

PC