ESSENTIALS OF DIAGNOSIS
Common normal flora but opportunistic pathogen.
Typically mucosal disease, particularly vaginitis and oral thrush/esophagitis.
Persistent, unexplained oral or vaginal candidiasis: check for HIV or diabetes mellitus.
(1,3)-beta-D-glucan results may be positive in candidemia even when blood cultures are negative.
Candida albicans can be cultured from the mouth, vagina, and feces of most people. Cutaneous and oral lesions are discussed in Chapters 6 and 8, respectively. Cellular immunodeficiency predisposes to mucocutaneous disease. When no other underlying cause is found, persistent oral or vaginal candidiasis should raise suspicion for HIV infection or diabetes. Risk factors for invasive candidiasis include prolonged neutropenia, abdominal surgery, broad-spectrum antibiotic therapy, corticosteroids, kidney disease, and the presence of intravascular catheters (especially when providing total parenteral nutrition). Although C albicans remains the most common cause of both mucocutaneous and systemic candidiasis, non-albicans strains are of considerable importance in certain contexts and may impact therapy owing to antifungal resistance.
Vulvovaginal candidiasis occurs in an estimated 75% of women during their lifetime. Risk factors include pregnancy, uncontrolled diabetes mellitus, broad-spectrum antimicrobial treatment, corticosteroid use, and HIV infection. Symptoms include acute vulvar pruritus, burning vaginal discharge, and dyspareunia.
Esophageal candidiasis may present clinically with symptoms of substernal odynophagia, gastroesophageal reflux, or nausea without substernal pain. Oral candidiasis, though often associated, is not invariably present. Diagnosis is best confirmed by endoscopy with biopsy and culture.
Most cases of candidal funguria are asymptomatic and represent specimen contamination or bladder colonization (and do not warrant antifungal therapy). However, symptoms and signs of true Candida urinary tract infections are indistinguishable from bacterial urinary tract infections and can include urgency, hesitancy, fever, chills, or flank pain.
Invasive candidiasis can be (1) candidemia (bloodstream infection) without deep-seated infection; (2) candidemia with deep-seated infection (typically eyes, kidney, or abdomen); and (3) deep-seated candidiasis in the absence of bloodstream infection (ie, hepatosplenic candidiasis). Varying ratios of these clinical entities depends on the predominating risk factors for affected patients (ie, neutropenia, indwelling vascular catheters, postsurgical).
The clinical presentation of candidemia varies from minimal fever to septic shock that can resemble a severe bacterial infection. The diagnosis of invasive Candida infection is challenging, since Candida species are often isolated from mucosal sites in the absence of invasive disease while blood cultures are positive only 50% of the time in invasive infection. Consecutively positive (1,3)-beta-D-glucan results may be used to guide empiric therapy in high-risk patients even in the absence of positive blood cultures.
Hepatosplenic candidiasis can occur following prolonged neutropenia in patients with underlying hematologic cancers, but this entity is less common in the era of widespread antifungal prophylaxis. Typically, fever and variable abdominal pain ...