[Septic arthritis? Gonococcal infection despite negative bacterial cultures]

Clinical signs of acute arthritis are non-specific. An acute painfull joint with effusion of unknown origin needs to be evaluated by puncture. The analysis of the synovial fluid will enable to divide an arthritis into three categories: crystal induced, rheumatological or septic arthritis. A bacterial infection should always be suspected. Cultures from blood, synovia and Gram stain do not reliably exclude a bacterial infection. If gonococcal, mycobacterial, borrelial and non-gonococcal-infective arthritis under antibiotic therapy is suspected, direct DNA-amplification can be helpful. A disseminated gonococcal infection (DGI) must be suspected on appearance of tenosynovitis, polyarthralgia and skin lesions. The clinical picture, diagnosis and therapy of a case with DGI is discussed.