Fungal arthritis

Inflammation induced by inoculation of the joint with Candida albicans

In humans Candida albicans is the most frequently isolated opportunistic fungal pathogen. In immunocompromized host the balance with the commensal fungus easily turns to life-threatening disseminated infection. The asymptomatic Candida persistence in organs and the recurrent infections suggest continuous circulation of yeast cells and their degradation products. Under certain conditions, joints might become one of the infectious sites. More easily a reactivation and destructive process can be provoked in individuals with established arthritis. We have investigated the joint inflammation caused by inoculation of the paw with live C. albicans, in intact mice and mice with collagen-induced arthritis (CIA). The results demonstrate that C. albicans infection when localized into the joints caused rapidly progressing septic arthritis. The effect was associated with a strong swelling, a rapid influx of polymorphonuclear (PMN) cells, and an elevated secretion of TNF-alpha and IFN-gamma by lymph node cells. Joint infection exacerbated the established CIA which correlated with an increased level of anti-collagen antibodies.

Mycotic osteomyelitis due to Scedosporium Apiospermum: MR imaging-pathologic correlation

Mycotic osteomyelitis is rare and occurs in immunocompromised patients after inoculation of the pathogen at a penetrating trauma site. Mycotic osteomyelitis due to Scedosporium Apiospermum is extremely rare, with only 13 cases of septic arthritis reported previously. Ours is only the third case of S. apiospermum osteomyelitis in an immunocompromised patient and the only patient with a histopathologic diagnosis from an amputation specimen. Recognition of this pathogen may be delayed due to insidious onset and negative joint fluid cultures, often requiring synovial or bone biopsies to establish the diagnosis. Delay in appropriate treatment may result in disseminating infection or even death.

Acute septic arthritis

Acute septic arthritis may develop as a result of hematogenous seeding, direct introduction, or extension from a contiguous focus of infection. The pathogenesis of acute septic arthritis is multifactorial and depends on the interaction of the host immune response and the adherence factors, toxins, and immunoavoidance strategies of the invading pathogen. Neisseria gonorrhoeae and Staphylococcus aureus are used in discussing the host-pathogen interaction in the pathogenesis of acute septic arthritis. While diagnosis rests on isolation of the bacterial species from synovial fluid samples, patient history, clinical presentation, laboratory findings, and imaging studies are also important. Acute nongonococcal septic arthritis is a medical emergency that can lead to significant morbidity and mortality. Therefore, prompt recognition, rapid and aggressive antimicrobial therapy, and surgical treatment are critical to ensuring a good prognosis. Even with prompt diagnosis and treatment, high mortality and morbidity rates still occur. In contrast, gonococcal arthritis is often successfully treated with antimicrobial therapy alone and demonstrates a very low rate of complications and an excellent prognosis for full return of normal joint function. In the case of prosthetic joint infections, the hardware must be eventually removed by a two-stage revision in order to cure the infection.

Septic arthritis due to Scedosporium apiospermum: case report and review

Septic arthritis is a relatively common disease, but reports of septic arthritis caused by fungi are still rare and it is often associated with predisposing factors that reduce cellular immunity (alcoholism, cancer, endogenous or exogenous hypercortisolism, intravenous drug abuse). Articular conditions caused by Scedosporium apiospermum are uncommon. Here we report the case of a 32-year-old immunocompetent male with septic arthritis caused by S. apiospermum and review 12 other cases.

Imaging of fungal, viral, and parasitic musculoskeletal and spinal diseases

There are many nonbacterial infections that have musculoskeletal manifestations and radiologic findings. These infections produce a limited range of tissue responses, depending on the organism, the tissue compartment affected, and the immune competence of the host. Diagnosis is dependent on obtaining an appropriate travel or geographic history, the clinical and laboratory features, and on occasion the specific radiologic findings.

A practical guide to the diagnosis and management of bone and joint infections

Infectious arthritis arises from haematogenous spread of organisms through the synovial membrane or from the direct extension of a contiguous infection. The diagnosis rests on the isolation of the pathogen(s) from joint fluid obtained by aspiration or from debridement. Synovial fluid analysis and Gram stains provide clues to the aetiology. The treatment of septic arthritis includes appropriate antimicrobial therapy and joint drainage. Bone infections are currently classified by the Waldvogel or Cierny-Mader classification. Cierny-Mader staging allows stratification and development of comprehensive treatment guidelines for each stage. Osteomyelitis therapy emphasises early diagnosis and aggressive treatment. Radiographs and bone cultures are the mainstays of diagnosis. Radionuclide scans, computerised tomography or magnetic resonance imaging may be obtained when the diagnosis of osteomyelitis is equivocal or to help gauge the extent of the infection. Medical therapy includes improving any host deficiencies, initial antibiotic selection and antibiotic modification based on culture results. Surgical treatment involves debridement of necrotic bone and tissue, obtaining appropriate cultures, managing dead space and, when necessary, obtaining bone stability.

Monarthritis: differential diagnosis

Acute monarthritis should be regarded as infectious until proved otherwise. Early evaluation is crucial because of the capacity of some infectious agents to destroy cartilage rapidly. The history and physical examination can provide highly suggestive clues, but a definitive diagnosis may depend on arthrocentesis and analysis of synovial fluid. The diagnosis of acute monarthritis is rarely established by radiography. The most common cause of bacterial arthritis is Neisseria gonorrhoeae. Staphylococcus aureus and streptococci are the organisms most frequently implicated in nongonococcal bacterial arthritis, although the possibility of Gram-negative bacteria or anaerobes should not be overlooked in intravenous drug users or immunocompromised patients. Inflammation in a large joint, particularly the knee, might arouse suspicion of Lyme disease. Other, less frequently encountered infectious causes of acute monarthritis include tuberculosis and other mycobacteria, fungi, and viruses. Arthroscopic examination and synovial tissue biopsy may be necessary to diagnose such processes. Microscopic examination of the synovial fluid may reveal a crystalline etiology for monarthritis. Monosodium urate crystals induce gout, usually in the toe, ankle, or midfoot, while calcium pyrophosphate crystals cause pseudogout, most often in the knee or wrist. Acute monarthritis is sometimes a manifestation of osteoarthritis or an early sign of a systemic arthritis such as rheumatoid or reactive arthritis. Processes underlying acute monarthritis can also evolve into a more chronic clinical picture as exemplified by the spondyloarthropathies.

Candida albicans arthritis one year after successful treatment of fungemia in a healthy infant

Fungal arthritis in pediatric patients is rare and is most often associated with hematogenous spread to the affected joint. It is generally seen concomitant with, or shortly after, fungemia. We report a case of an immunocompetent patient in whom candidal arthritis developed 1 year after initial fungemia. The initial candidiasis was considered to be adequately treated with amphotericin B. The Candida isolates from the neonatal fungemia and subsequent arthritis were the some as identified by electrophoretic karyotype, restriction fragment length polymorphism analysis, and antifungal susceptibility testing. Pediatric candidal fungemia, arthritis, and their treatments are discussed.

Candida albicans arthritis in a nonimmunocompromised patient. Complication of placebo intraarticular injections

A nonimmunocompromised 32-year-old man with arthrosis of the knee participated as a placebo control in a clinical trial of intraarticular injections of hyaluronan. After the fourth weekly injection of saline, he developed a warm and swollen knee, and synovial fluid cultures revealed growth of Candida albicans. Oral fluconazole treatment was instituted 2 weeks after onset of symptoms, but failed to eradicate the infection. The patient recovered after treatment with local and systemic amphotericin B, systemic 5-fluorocytosine and surgical synovectomy. Quantitation of joint cartilage proteoglycan fragments in synovial fluid indicated extensive breakdown of cartilage during the acute phase of arthritis but, parallel to clinical recovery, these levels returned to normal.