Table 3.

Diagnostic criteria for reactive arthritis

Major criteria	(1) Arthritis with 2 of 3 of the following findings
	- Asymmetric
	- Monoarthritis or oligoarthritis
	- Lower limb involvement
	(2) Preceding symptomatic infection with 1 or 2 of the following findings:
	- Enteritis (defined as diarrhoea for at least 1 day, and 3 days to 6 weeks before the onset of arthritis)
	- Urethritis (dysuria or discharge for at least 1 day, 3 days to 6 weeks before the onset of arthritis)
Minor criteria	At least one of the following:
	(1) Evidence of triggering infection:
	- Positive urine ligase reaction or urethral/cervical swab for Chlamydia trachomatis
	- Positive stool culture for enteric pathogens associated with reactive arthritis
	(2) Evidence of persistent synovial infection (positive immunohistology or PCR for Chlamydia)