Table 1 Specification of the variables used for the European Spondyloarthropathy Study Group (ESSG) criteria5
VariableDefinition
Inflammatory spinal pain*History or present symptoms of spinal pain in back, dorsal, or cervical region, with at least four of the following: (a) onset before age 45, (b) insidious onset, (c) improved by exercise, (d) associated with morning stiffness, (e) at least 3 months duration
SynovitisPast or present asymmetric arthritis or arthritis predominantly in the lower limbs
Family historyPresence in first-degree or second-degree relatives of any of the following: (a) ankylosing spondylitis, (b) psoriasis, (c) acute uveitis, (d) reactive arthritis, (e) inflammatory bowel disease
PsoriasisPast or present psoriasis diagnosed by a doctor
Inflammatory bowel diseasePast or present Crohn disease or ulcerative colitis diagnosed by a doctor and confirmed by radiographic examination or endoscopy
Alternating buttock painPast or present pain alternating between the right and left gluteal regions
EnthesopathyPast or present spontaneous pain or tenderness at examination at the site of the insertion of the Achilles tendon or plantar fascia
Acute diarrhoeaEpisode of diarrhoea occurring within 1 month before arthritis
Urethritis/cervicitisNon-gonococcal urethritis or cervicitis occurring within 1 month before arthritis
SacroiliitisBilateral grade 2–4 or unilateral grade 3–4, according to the following radiographic grading system: 0 = normal, 1 = possible, 2 = minimal, 3 = moderate and 4 = ankylosis
  • *Equivalent to inflammatory back pain (IBP).