Painful, swollen elbow

Diagnosis: Iatrogenic septic olecranon bursitis

Aspiration of the patient’s olecranon bursa produced 3 mL of cloudy fluid (FIGURE 2). The patient’s painful, swollen, erythematous, warm elbow, cloudy aspirate, and history of preceding PIN hydrodissection were consistent with a diagnosis of septic olecranon bursitis.

PHOTO COURTESY OF MORTEZA KHODAEE, MD, MPH

When septic bursitis is strongly suspected or confirmed, the patient should be started on an antibiotic regimen that covers S aureus.

Septic bursitis usually is caused by bacteria.^1,2 Bursal infection can result from the spread of infection from nearby tissues or direct inoculation from skin trauma. It can also be iatrogenic and occur among healthy individuals.^2,3 Injection anywhere close to the bursa can inoculate enough bacteria to progress to cellulitis first and then septic bursitis. Inflammatory conditions such as gout and rheumatoid arthritis also can cause acute and/or chronic superficial bursitis.^1,2,4

Differentiating between septic and nonseptic bursitis can be challenging on history and physical exam alone, but specific signs and symptoms should warrant concern for infection.^1,2,4,5 Fever is present in up to 75% of septic cases⁵; however, lack of fever does not rule out septic bursitis. Pain, erythema, warmth, and an overlying skin lesion also can indicate infection.⁴ Diagnostic imaging modalities may help distinguish different types of olecranon bursitis, but in most cases, they are not necessary.²

Other joint disorders factor into the differential

The differential diagnosis is broad and includes a variety of joint disorders in addition to septic (and nonseptic) bursitis.^2,3

Septic arthritis is a deeper infection that involves the elbow joint and is considered an orthopedic emergency due to potential joint destruction.

Continue to: A simple joint effusion