DESCRIPTION

Candidiasis is an infection caused by species of the yeast Candida resulting in a wide spectrum of disease.

• Mucocutaneous infections include oral thrush, vaginal or cervical disease, infections of skin folds, and esophagitis or laryngitis.
• Recurrent candidal infections, esophageal or laryngeal disease may be the presenting symptom of immunodeficiency.
• Invasive disease includes bloodstream infection or candidemia, disseminated candidiasis, endocarditis, central nervous system (CNS) infection, osteomyelitis, and catheter-associated peritonitis and urinary tract infections.

ETIOLOGY

>15 species of Candida cause human disease with 95% of infections caused by Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Candida species may cause disease at any site.

• Superficial infections include thrush (oropharyngeal candidiasis) and diaper dermatitis, both of which are most common in infancy and intertriginous candidiasis which occurs in skinfolds generally in healthy patients with chronic moisture, recent antibiotic use, or obesity.
• Esophagitis results in mucosal irregularities and swallowing difficulty and is seen with primary immune deficiencies and is an AIDS defining illness.
• Chronic mucocutaneous candidiasis is caused by a T-cell defect resulting in decreased production of Candida-specific antibody resulting in a superficial infection of the skin, hair, mucous membranes, and nails.
• Congenital cutaneous candidiasis is a rare ascending infection into the uterus prior to birth that causes a diffuse red rash.
• Invasive candidiasis may be isolated to the blood stream; that is, candidemia or disseminated candidiasis with fungal invasion of the liver, spleen, bone, kidneys, and/or brain. Fungal sepsis may occur.

EPIDEMIOLOGY

• Candida species are common, ubiquitous yeast. C. albicans is part of the normal human microbiome and lives on the skin, in the mouth, in intestinal tract, and in vaginal mucosa.
• Vulvovaginitis is associated with pregnancy and can be transmitted to the newborn infant in utero, during delivery, or after birth.
  • Neonatal thrush and vaginal candidiasis occur mainly in healthy hosts.
  • Mild mucocutaneous disease is common in young infants.
• Candidiasis is an opportunistic infection.
  • Invasive disease and chronic or recurrent mucocutaneous disease are associated with AIDS, primary immunodeficiency (neutrophil defects), and cancer treatment.
• Person-to-person transmission is rare.
• The incubation period is unknown.

RISK FACTORS

• General risk factors:
  • Corticosteroid use
  • Broad-spectrum antibiotic use
  • Diabetes mellitus
  • AIDS
  • Cancer chemotherapy
  • Neutrophil defects
  • Organ transplantation
  • Indwelling catheters
  • Intravenous alimentation
• Oral thrush occurs mainly in babies in the 1st month of life, the elderly, and persons with immune compromise. Candida may live on oral devices like bottle nipples, pacifiers, and dentures causing recurrent or prolonged infection.
• Intertriginous candidiasis is associated with obesity.
• Genital candidiasis is more common in pregnancy.
• Invasive candidiasis is often a health care–associated infection and is associated with central venous catheters, intensive care unit (ICU) stay, dialysis, renal failure, and gastrointestinal surgery.

GENERAL PREVENTION

• Clean bottles, nipples, and pacifiers in hot water.
• Maintain oral hygiene and rinse mouth after using inhaled steroids.
• Avoid unnecessary antibiotic use and limit antibiotic duration.
• Remove indwelling catheters as soon as possible and use of bundles to prevent catheter infections.
• Ensure proper hygiene with urine catheters and peritoneal dialysis catheters.

PATHOPHYSIOLOGY

Candida species are yeast that reproduce via budding.

• Mucocutaneous disease is typically caused by the host’s own organisms.
  • Changes in vaginal pH or hormonal changes may predispose to genital disease.
  • Oral and skin infections occur when diseases like cancer or diabetes or medications like antibiotics or steroids cause imbalance in the normal environment.
• Invasive disease occurs when Candida species enter the bloodstream and spread through the body. Invasive infection is often health care–associated and related to catheter use including bloodstream central venous lines and urinary and peritoneal catheters.

COMMONLY ASSOCIATED CONDITIONS

• Diabetes mellitus
• Cancer
• Organ transplant
• Primary neutropenia
• AIDS
• Obesity