SHM Converge Scientific Abstract ePoster Gallery-Rare Case of Salmonella Septic Arthritis

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This case describes a 69-year-old woman with systemic lupus erythematosus (SLE) and recent COVID-19 infection who presented with one week of worsening right knee pain and swelling, plus a fever to 40°C. She was taking hydroxychloroquine and prednisone. Exam showed a hot, swollen, erythematous right knee (hydrops), with otherwise normal joints. Labs revealed markedly elevated CRP (184 mg/L) but normal creatinine and CBC. Knee X-ray showed mild chondrocalcinosis. Joint aspiration produced cloudy fluid without crystals, making crystal arthritis less likely. Serologies showed normal anti-dsDNA, C3, and C4, arguing against an active lupus flare.<br /><br />The differential diagnosis included septic arthritis, reactive arthritis, crystal arthropathy, osteoarthritis, and COVID-related SLE flare. She was initially treated empirically with cefuroxime and gentamicin. Cultures from both synovial fluid and blood grew Salmonella group D, confirming Salmonella septic arthritis (SSA). Antibiotics were then narrowed to ceftriaxone.<br /><br />The discussion highlights that Salmonella is a Gram-negative rod commonly associated with poultry exposure and undercooked chicken, typically causing gastroenteritis after an incubation period of 6 to 72 hours. Bacteremia occurs in fewer than 5% of infections, and septic arthritis is rare. However, SLE patients are at increased risk because of impaired immune clearance, especially when receiving immunosuppressive therapy. Salmonella can cause either reactive arthritis or true septic arthritis through hematogenous spread. Chronic carrier state should be considered in patients with prior Salmonella infection, particularly before starting immunosuppression.<br /><br />Overall, this report emphasizes that Salmonella septic arthritis, though uncommon, should be considered in febrile SLE patients with acute monoarthritis.

Asset Subtitle

Babray Laek

Meta Tag

Author List Babray Laek, Jalil Makhkash

Category Clinical Vignettes

Concept Salmonella

Concept Gastroenteritis

Concept Septic Arthritis

Concept Joint Aspiration

Concept Systemic Lupus Erythematosus

Distinguished Non-Finalist

Presenter Organization UPMC McKeesport

Presenting Author Babray Laek

Track Adult

Keywords

systemic lupus erythematosus

Salmonella septic arthritis

acute monoarthritis

fever

knee swelling

bacteremia

immunosuppression

synovial fluid culture

chondrocalcinosis

ceftriaxone

Salmonella

Gastroenteritis

Septic Arthritis

Joint Aspiration

Systemic Lupus Erythematosus