kandidiasis

Kandidiasis is a fungal infection caused by yeasts of the genus Candida. Candida species are common inhabitants of the human microbiota, particularly in the mouth, gastrointestinal tract and vagina. Disease occurs when the yeasts overgrow or invade tissues, ranging from superficial mucosal infections to invasive, life-threatening disease. The most frequently implicated species is Candida albicans, though non-albicans species such as C. glabrata, C. tropicalis and C. parapsilosis are increasingly encountered.

Clinical forms include mucosal infections such as oropharyngeal candidiasis (thrush), esophageal candidiasis, and vulvovaginal candidiasis. Cutaneous candidiasis affects moist skin areas, including diaper rash and intertriginous folds. In immunocompromised individuals or those with central venous catheters or prior broad-spectrum antibiotic exposure, candidemia and invasive candidiasis can occur, potentially involving the blood, liver, spleen, kidneys, eyes or central nervous system.

Diagnosis relies on clinical assessment supported by laboratory testing. Microscopy with potassium hydroxide preparation, and culture on appropriate media (often Sabouraud dextrose) are common. Species identification guides treatment choices. For suspected invasive disease, blood cultures are important; nonculture tests such as β-D-glucan can aid in assessment but are not species specific.

Treatment depends on the form and severity. Superficial infections are typically treated with topical azoles (eg, clotrimazole, miconazole) or nystatin; uncomplicated vulvovaginal candidiasis may respond to a single oral dose of fluconazole or topical therapy. Esophageal candidiasis and invasive candidiasis require systemic antifungal therapy, usually an echinocandin as initial treatment, with step-down to fluconazole when susceptible. Resistance, particularly among C. glabrata and emerging species such as C. auris, is a concern and influences therapy.

Prevention focuses on addressing risk factors, including judicious antibiotic use, good glycemic control, meticulous care of invasive devices, and prompt evaluation of new fever or sepsis in high-risk patients.