Comparison of Gonococcal and Non-Gonococcal Septic Arthritis
| Gonococcal septic arthritis | Non-gonococcal septic arthritis | |
|---|---|---|
| Organisms | Neisseria gonorrhoeae | Staphylococcus aureus Beta-haemolytic streptococci Streptococcus pneumoniae Gram-negative rods |
| Patient profile | Young, healthy, sexually active | Elderly, rheumatoid arthritis, prosthetic joint, IV drug use, bacteraemia, immunosuppression |
| Initial presentation | Migratory polyarthralgia, tenosynovitis, dermatitis | Typically with a single hot, swollen, painful joint, but can be poly-articular (15% of cases) |
| Joints involved | Often poly-articular, especially knee and wrist | Knee joint most commonly involved, followed by the elbow, shoulder and hip |
| Other signs | Tenosynovitis, rash | Source of bacteraemia |
| Gram stain of synovial fluid | <25% positive | 50–75% positive |
| Culture of synovial fluid | 25% positive | 85–95% positive |
| Blood culture | <10% positive | 50% positive |
| Genitourinary culture (swab of urethra, cervix and anorectum) | 80% positive | Not indicated |