Osteomyelitis Differential Diagnoses

Updated: Jul 11, 2022
  • Author: Jigar Gandhi, MD, PharmD; Chief Editor: Murali Poduval, MBBS, MS, DNB  more...
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Diagnostic Considerations

Crystal arthropathies (gout and pseudogout) presents in a similar manner to septic arthritis. The diagnosis can be made by means of polarized microscopic examination of monosodium urate crystals in gout or calcium pyrophosphate crystals in pseudogout. [21]  

In children, Ewing sarcoma is a common form of bone malignancy. It presents with clinical symptoms of fever, pain, malaise, and swelling, which are very similar to those of osteomyelitis. Invasion of the tumor into the periarticular space is uncommon but, if present, can radiographically mimic septic arthritis. [22]  

Septic arthritis generally presents with acute pain, swelling, warmth, and decreased range of motion (ROM) in a single joint. Only 40-60% of patients will have a fever at presentation. Laboratory studies and synovial fluid analysis are helpful for diagnosis. [21]  The demarcation between the two can be often difficult and requires careful clinical examination and, sometimes, arthrocentesis to test joint fluid.

In patients with sickle cell disease, it can be challenging to differentiate between a vaso-occlusive crisis and an infection such as osteomyelitis. An infectious etiology is less likely if more than one area of the body is affected. Osteomyelitis also tends to have clinical symptoms (eg, pain, swelling, and fever) developing over a longer time course than a vaso-occlusive crisis. [23]

Clinical suspicion, presence of deep bony tenderness, local signs of inflammation, and symptoms of acute clinical infection are helpful in initiating a diagnosis of acute osteomyelitis where radiologic signs may be absent or minimal and time is of the essence.

Differential Diagnoses