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(See also Fungal Skin Infections: Candidiasis, see also Vaginitis and Pelvic Inflammatory Disease (PID): Candidal Vaginitis, and see also Immunodeficiency Disorders: Chronic Mucocutaneous Candidiasis)
Candidiasis
is infection by Candida sp (most often C.
albicans), manifested by mucocutaneous lesions,
fungemia, and sometimes focal infection of multiple sites. Symptoms
depend on the site of infection and include dysphagia, skin and
mucosal lesions, blindness, vaginal symptoms (itching, burning,
and discharge), fever, shock, oliguria, renal shutdown, and disseminated
intravascular coagulation. Diagnosis is confirmed by histopathology
and cultures from normally sterile sites. Treatment is with amphotericin
B, fluconazole, echinocandins, voriconazole, or posaconazole.
(See also the Infectious Diseases Society of America's Guidelines
for Treatment of Candidiasis.)
Candida sp are commensal organisms that inhabit the GI tract and sometimes the skin (see Fungal Skin Infections: Etiology). Unlike other systemic mycoses, candidiasis results from endogenous organisms. Most infections are caused by C. albicans or C.
tropicalis; however, C. glabrata (formerly Torulopsis
glabrata) is increasingly involved in fungemia, UTIs, and, occasionally, pneumonia or other focal disease.
Candida sp account for about 80% of major systemic fungal infections and are the most common cause of fungal infections in immunocompromised patients. Candidal infections are one of the most common hospital-acquired infections.
Candidiasis involving the mouth and esophagus is a defining opportunistic infection in AIDS. Although mucocutaneous candidiasis is frequently present in HIV-infected patients, hematogenous dissemination is unusual until immunosuppression becomes profound. Neutropenic patients (eg, those receiving cancer chemotherapy) are at high risk of developing life-threatening disseminated candidiasis.
Candidemia may occur in nonneutropenic patients during prolonged hospitalization. This bloodstream infection is often related to one or more of the following:
IV lines and the GI tract are the usual portals of entry. Candidemia often prolongs hospitalization and increases mortality due to concurrent disorders. Prolonged or untreated candidemia may lead to endocarditis or meningitis as well as to focal involvement of skin, subcutaneous tissues, bones, joints, liver, spleen, kidneys, eyes, and other tissues. Endocarditis is commonly related to IV drug abuse, valve replacement, or intravascular trauma induced by indwelling IV catheters.
All forms of disseminated candidiasis should be considered serious, progressive, and potentially fatal.
Symptoms and Signs
Esophagitis is most often manifested by dysphagia. Symptoms of respiratory tract infections (eg, cough) are nonspecific.
Candidemia usually causes fever, but no symptoms are specific. Some patients develop a syndrome resembling bacterial sepsis, with a fulminating course that may include shock, oliguria, renal shutdown, and disseminated intravascular coagulation.
Candidal endophthalmitis starts as white retinal lesions that are initially asymptomatic but can progress, opacifying the vitreous and causing potentially irreversible scarring and blindness. In neutropenic patients, retinal hemorrhages occasionally also occur, but actual infection of the eye is rare.
Papulonodular skin lesions may also develop, especially in neutropenic patients; in whom they indicate widespread hematogenous dissemination to other organs. Symptoms of other focal infection depend on the organ involved.
Diagnosis
Because Candida spp are commensal, their culture from sputum, the mouth, the vagina, urine, stool, or skin does not necessarily signify an invasive, progressive infection. A characteristic clinical lesion must also be present, histopathologic evidence of tissue invasion (eg, yeasts, pseudohyphae, or hyphae in tissue specimens) must be documented, and other etiologies must be excluded. Positive cultures of blood, CSF, pericardium or pericardial fluid, or tissue biopsy specimens provide definitive evidence that systemic therapy is needed.
Serologic assays do not have sufficient specificity or sensitivity to be useful.
Treatment
Predisposing conditions (eg, neutropenia, immunosuppression, use of broad-spectrum antibacterial antibiotics, hyperalimentation, presence of indwelling lines) should be reversed or controlled if possible. IV amphotericin B is recommended for most severely ill patients, especially those who are immunosuppressed. Echinocandins are an alternative to amphotericin B in adults with or without neutropenia. Fluconazole 400 to 800 mg po once/day is also considered a first-line drug (unless C. krusei or C.
glabrata is involved) for nonneutropenic patients and may be effective in patients with neutropenia.
Esophageal candidiasis is treated with fluconazole 200 to 400 mg po or IV once/day or itraconazole 200 mg po once/day. If these drugs are ineffective or if infection is severe, voriconazole 4 mg/kg po or IV bid, posaconazole 400 mg po bid, or one of the echinocandins may be used. These drugs are also effective for bloodstream and other hematogenously disseminated infections.
Last full review/revision April 2009 by Alan M. Sugar, MD
Content last modified April 2009
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