What is the relationship between psoas abscess and brucellosis (Brucella infection)?

From the Guidelines

Brucellosis-associated psoas abscess requires aggressive treatment with a combination of antibiotics and possible surgical drainage. The management of psoas abscess, as described in the practice guidelines for the diagnosis and management of skin and soft-tissue infections 1, involves appropriate antibiotics plus extensive surgical incision and drainage.

Key Considerations

• The condition often presents with localized pain in a single muscle group, muscle spasm, and fever, and can be diagnosed using ultrasonography or CT scan to differentiate it from deep venous thrombosis 1.
• Blood culture results are positive in 5%–30% of cases, and the disease can occur in any muscle group, including the psoas or trunk muscles 1.
• The slow-growing nature of Brucella organisms necessitates prolonged antibiotic therapy to prevent relapse, which occurs in 5-15% of cases.

Treatment Approach

• The recommended antibiotic regimen consists of doxycycline and rifampin for at least 6 weeks, often extended to 8-12 weeks for complicated cases.
• Surgical drainage is indicated for large abscesses, those causing significant symptoms, or when medical therapy fails.
• CT-guided percutaneous drainage is preferred when feasible, with open surgical drainage reserved for complex or multiloculated abscesses.

Monitoring and Follow-up

• Patients require close monitoring with regular blood tests, imaging follow-up, and clinical assessment for treatment response.
• Complete resolution typically requires both appropriate antimicrobial therapy and adequate drainage of purulent collections.

From the Research

Psoas Abscess and Brucellosis

• Psoas abscess is a rare entity that can be caused by various micro-organisms, including Brucella melitensis 2.
• Brucellar psoas abscess is very rare, even in countries where Brucella is highly endemic, such as Turkey 2.
• The clinical presentation of psoas abscesses is often non-specific, making early aetiological diagnosis crucial for appropriate treatment 2.

Diagnosis and Treatment

• Diagnosis of brucellosis is typically made through a combination of clinical signs, serological tests, and positive blood or synovial fluid cultures 3.
• The standard agglutination test (SAT) titer ≥1:160 is indicative of brucellosis diagnosis 3.
• Treatment of brucellosis typically involves a combination of antibiotics, such as doxycycline, streptomycin, and rifampicin, for a period of at least three months 3, 4.
• Psoas abscesses can be treated with antibiotics alone, or with percutaneous drainage or surgery in more complicated cases 5, 6.

Complications and Outcomes

• Psoas abscesses can be a complication of spondylitis, which is a common manifestation of osteoarticular brucellosis 3, 6.
• The mortality rate for psoas abscesses is relatively low, around 3%, and most patients can be successfully treated with non-surgical interventions 5.
• Early diagnosis and treatment are essential for preventing long-term complications and achieving complete resolution of symptoms 2, 3.