clinical characteristics of postenteritic reactive arthritis
• Demographically, males are affected more frequently than females; average age is 30 years old.
• Onset of arthritis is abrupt and acute.
• Distribution of joints is asymmetric and oligoarticular. A lower extremity is involved in 80% to 90%. Sacroiliitis occurs in 20% to 30%; enthesitis (Achilles tendon, plantar fascia attachments) and toe dactylitis occur.
• Synovial fluid analysis finds inflammatory fluid (usually 10,000-50,000 WBC/mm 3 ), no crystals, and negative cultures.
• Course and prognosis finds that 80% resolve in 1 to 6 months; 20% have chronic arthritis with radiographic changes of peripheral and/or sacroiliac joints.