Practice Essentials
Candidal infections are extremely common (see the images below).
Typical appearance of thrush. Note multiple white plaques on lips, gingivae, tongue, and palate.
Candidal diaper dermatitis. Note satellite papules and involvement of intertriginous folds.
Candida albicans is the most common cause of human candidal infections, [1] but other pathogenic species include Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei, Candida lusitaniae, and Candida stellatoidea.
Signs and symptoms
Thrush
Infants may experience pain, poor feeding, or fussiness. White plaques are observed in the mouth and may affect the lips, tongue, gums, and palate.
Cutaneous candidiasis
Patients report itching, burning, and soreness. Most commonly affected areas are the diaper area in infants and toddlers and abdominal fat folds and groin in older individuals.
Paronychia and onychomycosis
Paronychia typically involves the cuticular fold of fingernails, causing redness, swelling, and pain.
Nail involvement usually stems from long-standing paronychia and causes a yellow discoloration of the nail, often with separation of the nail from the nail bed.
Genital candidiasis
With vulvovaginitis, a creamy white discharge is usually present, and white plaques may be observed on an erythematous base of the vaginal mucosa or vulvar skin.
With balanitis, lesions are usually observed on the glans penis and consist of erythematous plaques, pustules, or erosions.
Otitis externa
Tenderness of the pinna, aural discharge, and erythema are characteristic.
GI candidiasis
Common in infants, glossitis is characterized by creamy or curdlike white plaques, which may be painful and bleed beneath when scraped.
Symptoms of esophagitis include dysphagia and odynophagia.
Endophthalmitis
White well-circumscribed lesions of the retina and choroid in the posterior pole are characteristic.
CNS infections
CNS infections usually present as subacute meningitis.
Endocarditis
Endocarditis is characterized by fever and a new or changing heart murmur.
Hepatic (hepatosplenic) candidiasis
Hepatic candidiasis may present with fever of unknown origin. It is usually a manifestation of disseminated candidiasis.
See Presentation for more detail.
Diagnosis
Laboratory studies
The following studies are indicated in candidiasis:
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Potassium hydroxide (KOH) slide preparation
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Cultures
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Beta-glucan assay
Imaging studies
Ultrasonography and computed tomography (CT) scanning may be helpful in making the diagnosis of disseminated candidal infection in immunocompromised patients, especially for renal, bladder, hepatic, and splenic lesions.
Endoscopy may be indicated for diagnosis of candidal esophagitis
See Workup for more detail.
Management
Treatment of candidal infections is primarily accomplished with appropriate antifungal drugs.
See Treatment and Medication for more detail.
Pathophysiology
Infections caused by Candida may affect numerous organ systems, such as the eyes, lungs, kidneys, heart, and CNS.
Skin
The most common manifestation of candidal infection is diaper dermatitis in infants. Candida organisms can also cause intertrigo in older individuals. Intertrigo has a predilection for dark moist areas, such as the groin or fat folds. Predisposing conditions include diabetes mellitus, obesity, and hyperhidrosis.
Nails
A chronic paronychia may be caused by one of several Candida species. Candida organisms can also cause onychomycosis, including total nail dystrophy due to chronic mucocutaneous candidiasis (CMCC), a rare T-cell disorder.
Mucous membranes
Thrush, or oral candidiasis, is also common in infants. Oral candidiasis may also be an adverse effect from using inhaled corticosteroids for asthma due to oral deposition. Patients who are immunocompromised may suffer from candidal esophagitis as well as thrush.
Genitals
Vaginal yeast infections affect nearly 75% of women. Male partners may develop balanitis or balanoposthitis. Individuals with chronic indwelling catheters are also predisposed to recurrent candidal infections.
Systemic
Candida organisms can cause severe systemic infections in immunocompromised patients, compared with benign cutaneous or localized infections in immunocompetent patients. Reports of systemic candidiasis are common in children with acquired immunodeficiency syndrome (AIDS) and other immune deficiencies, as well as in very low birth weight premature infants. Risk factors for candidemia in critically ill children have been identified. [2, 3] Manifestations include fungemia, endophthalmitis, meningitis, renal or bladder bezoars, and arthritis.
Virulence factors
Numerous factors can contribute to the likelihood of candidal infections. An intact skin barrier is protective. Candidal infections are promoted in the face of lymphocyte dysfunction, as is observed in persons with AIDS and those with CMCC. Adherence of Candida organisms to oral and vaginal epithelium is believed to be promoted by biologic factors (eg, fibronectin in thromboses) and by iatrogenic factors (eg, presence of plastic catheters, disruption of normal bacterial flora). In neonates, risk factors include indwelling catheters, prolonged antibiotic use, necrotizing enterocolitis, previous bloodstream infections, total parenteral nutrition, and low birth weight.
Chronic mucocutaneous candidiasis
CMCC is a heterogeneous group of disorders characterized by chronic candidal infections of the nails, skin, and mucous membranes. Most CMCC disorders are autosomal recessive and related to a mutation in the AIRE gene. [4] Lymphocyte numbers are normal; however, response to in vitro exposure to candidal antigen is absent.
Etiology
Candidal infections have differing presentations in patients who are immunocompetent versus persons who are immunocompromised.
Patient who is immunocompetent
Although candidal diaper rash is common in healthy infants, predisposing factors causing candidal infections in older individuals are often present.
The most common factor is the disruption of normal flora following a course of antibiotic therapy, which is most commonly observed as cutaneous candidiasis or vulvovaginitis.
Other risk factors for candidal infection relate to impaired immune function, including individuals with diabetes mellitus, premature infants, hosts who are immunocompromised, and persons using systemic or topical corticosteroids.
Other risk factors include obesity, heat, and excessive sweating.
Patient who is immunocompromised
Individuals who are immunocompromised, including AIDS, are more susceptible to oral and cutaneous candidiasis and often have a more severe course.
Oral candidiasis may appear as acute or chronic atrophic candidiasis, which causes painful red erosions of the tongue and mucous membranes.
Candida species are frequent causes of central venous catheter infections.
Immunosuppression may also cause systemic candidiasis, which may present as fungemia or funguria. Candida species may cause fungal bezoars in the kidney or bladder, or candidiasis may cause abscesses in the liver or spleen. Candidal meningitis, arthritis, and endophthalmitis all have been reported.
Neonates
Neonates with very low birth weight are at a higher risk of developing candidemia. Risk factors include low birth weight, preterm birth, broad spectrum antibiotic use, total parental nutrition, previous bloodstream infections, and necrotizing enterocolitis. [5]
Potentially modifiable risk factors associated with invasive candidiasis in neonates include the presence of an endotracheal tube or a central venous catheter and receipt of an intravenous lipid emulsion. [6]
Chronic mucocutaneous candidiasis (CMCC)
CMCC is a cluster of disorders of cell-mediated immunity that presents as chronic severe candidal infections of the skin and mucous membranes.
Epidemiology
United States statistics
Thrush occurs in approximately 2-5% of healthy newborns and a slightly higher percentage of infants in the first year of life. Vaginal candidal infections occur in approximately 75% of women, and 40-50% of women experience recurrence. Approximately 2-5% of premature infants weighing less than 1500 g develop disseminated disease. [7]
Race-, sex-, and age-related demographics
No racial predilection is noted.
Vaginal candidiasis is a frequent problem among women and adolescent girls. No gender predilection is noted in other forms of candidiasis.
In the healthy host, candidal infections are most common in the first year of life as thrush or diaper dermatitis. Vulvovaginitis is more common in adolescent and adult females.
Prognosis
Prognosis for oral or cutaneous candidiasis is excellent with appropriate medical treatment.
Systemic candidiasis, especially in low birth weight premature infants, carries a high rate of morbidity and mortality. Even with appropriate treatment, mortality may reach 50% in this population. [8]
Morbidity/mortality
Candidal infections rarely cause significant morbidity in the healthy host. However, systemic disease may be found in as many as 15% of patients who are neutropenic. Mortality in low birth weight premature infants with systemic candidiasis may reach 50%. Candida is the second leading cause of sepsis in critical care patients.
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Typical appearance of thrush. Note multiple white plaques on lips, gingivae, tongue, and palate.
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Candidal diaper dermatitis. Note satellite papules and involvement of intertriginous folds.
