The Four Overlapping Forms of Invasive Candidiasis
The Four Forms of Invasive Candidiasis (from )
Defining the various forms of invasive candidiasis is a challenge. We follow the concepts first proposed by Bodey, Anaissie, & Edwards in their 1993 analysis . As discussed in our overview of invasive candidiasis, essentially all forms of invasive candidiasis begin as an episode of candidemia. However, the degree to which this is clinically obvious varies (figure). From a clinical standpoint, these four forms of invasive candidiasis are sufficiently different that separating them is useful:
- Catheter-Related Candidemia
Candidemia due to infection of a vascular catheter is arguably the most common form of invasive candidiasis. The key feature of this disease is that the primary infection is of the catheter and/or the fibrin clot that forms around the catheter. Not surprisingly, removal of the catheter significantly ameliorates the disease. But, drug therapy is still required, both to speed clearance of any local infection and to assist with clearance of undetected foci of hematogenous spread. For more details, see our discussion of intravascular catheters and management of candidemia.
- Acute Disseminated Candidiasis
In this form, candidemia is present and may well have originated from an infected catheter. But, the special feature of this form is that spread to one or more organs is now apparent. Even if a vascular catheter was once or is still involved, the disease is now so extensive that the catheter represents only a small component of the infection. Treatment focuses on elimination of any primary focus of infection, control of the signs and symptoms of sepsis, and drug therapy to speed clearance of all sites of infection.
- Chronic Disseminated Candidiasis
This form of candidiasis has also been referred to as hepatosplenic candidiasis. It occurs almost exclusively following the prolonged episodes of bone marrow dysfunction and neutropenia that occur during treatment for leukemia. In this form of invasive candidiasis, the liver, spleen, and sometimes kidney are prominently infected with Candida. Radiologic studies demonstrate characteristic lucencies of these organs. Blood cultures are rarely positive at this point, although presumably they were positive at the time the infection was initiated.
- Deep Organ Candidiasis
Virtually any organ of the body may be affected, either in isolation or in combination. In each case, an episode of candidemia must have led to seeding of the affected area. But, at the time of presentation the blood is sterile and the focal infection of the specific organ is the only manifestation. These forms can present in any patient who had, or was at risk for, candidemia. This is the feature that sets these manifestations apart from hepatosplenic candidiasis. While hepatosplenic candidiasis (chronic disseminated candidiasis) is also a form of deep organ candidiasis, its unique clinical setting (following the prolonged neutropenia of therapy for hematological malignancy) sets it apart from these forms of invasive disease:
Bone & Joint Candidiasis
Brain & Nerves (CNS candidiasis)
Gallbladder (Biliary Candidiasis)
Heart (Cardiac Candidiasis)
Lung (Candida Pneumonia)
Kidney & Bladder (Urinary Candidiasis)
Liver & Spleen (Hepatosplenic Candidiasis)
Pancreas (Pancreatic Candidiasis)