Septic Arthritis Differential Diagnoses

Updated: Sep 19, 2017
  • Author: John L Brusch, MD, FACP; Chief Editor: Michael Stuart Bronze, MD  more...
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DDx

Diagnostic Considerations

When evaluating a patient with suspected septic arthritis, also consider conditions such as primary rheumatologic disorders (eg, vasculitis, crystalline arthritides), drug-induced arthritis, and reactive arthritis (eg, postinfectious diarrhea syndrome, postmeningococcal and postgonococcal arthritis, arthritis of intrinsic bowel disease [15] ).

In early disseminated gonococcal infection, an early tenosynovitis predominates without actual joint invasion such as occurs in the later variety of disseminated gonococcal infection. A viral syndrome usually produces polyarticular arthritis. Pustular lesions are consistent (as is almost any type of skin lesion) with staphylococcal bacteremia. Whenever vesicles are present, always consider staphylococcal infection.

Unlike salmonella osteomyelitis, the frequency of salmonella septic arthritis is not greatly increased in patients with sickle cell anemia. However, when septic arthritis does occur, Salmonella is more commonly identified.

Staphylococcus aureus remains the most common infectious agent in people who abuse intravenous drugs. However, a high rate of infections with gram-negative organisms, especially Pseudomonas aeruginosa and Serratia species, occurs in cases of septic arthritis. In addition, a higher rate of fungal and anaerobic infections occurs. Unusual locations, such as the sternoclavicular joint, are involved.