Oral Candidiasis

Baby With White Plaques on the Tongue

University of Calgary

Dr Wong is clinical assistant professor of family medicine at the University of Calgary.

Alexander K. C. Leung, MD—Series Editor: Dr Leung is clinical professor of pediatrics at the University of Calgary and pediatric consultant at the Alberta Children’s Hospital in Calgary.

Oral Candidiasis


A 3-month-old girl born to a 24-year-old, gravid 2, para 1 mother at 37 weeks’ gestation after an uncomplicated pregnancy and normal spontaneous delivery presented with a white tongue. Apgar scores were 5 at 1 minute and 9 at 5 minutes. Birth weight was 3.1 kg and length 49.5 cm. Breastfed, thriving infant. Neither mother nor infant were taking an antibiotic. Neonatal course uneventful.


White, curd-like, discrete plaques on the tongue and palate. Remaining examination findings unremarkable. In particular, no diaper rash.

(Answer on next page) 

What's Your Diagnosis?
: Oral Candidiasis

Candidiasis is the most common fungal infection of the mouth.1 Candida is an oral commensal fungus found in 45% to 65% of healthy infants and 30% to 55% of healthy adults.2,3 In general, it becomes pathogenic when the host immune defense is undermined.4


Candida albicans is most often associated with oral disease.4,6 Oral candidiasis can also be caused by Candida glabrata, Candida tropicalis, Candida krusei, Candida parapsilosis, Candida guilliermondii, Candida lusitaniae, Candida stellatoidea, and Candida dubliniensis.3,5,6 The fungus can be acquired at delivery during passage through an infected birth canal, from the skin of the mother’s breast during nursing, and from contaminated fomites (such as pacifiers and bottle nipples).1

Oral candidiasis affects 2% to 5% of otherwise healthy newborns.1 The incidence is much higher in premature and very low birth weight infants.7 Oral candidiasis is rare after 12 months of age but can occur in older children with risk factors. These include use of broad-spectrum antibiotics, use of inhaled or systemic corticosteroids, diabetes mellitus, xerostomia, and immunodeficiency.2,5,8,9


The most common presentation is pseudomembranous candidiasis (thrush), which is characterized by white, curd-like, discrete plaques on any part of the oral mucosa.1,5,8 The adherent pseudomembrane is composed of desquamated epithelial cells, keratin, leukocytes, necrotic tissue, and food particles. Wiping off the plaques may reveal raw, erythematous, and sometimes bleeding mucosa underneath.1 Erythematous, or atrophic, candidiasis, manifests as smooth erythematous patches often on the palate, gum, and dorsum of the tongue.1,5,8 The color intensity may vary from fiery red to a hardly discernable pink spot.8

Oral candidiasis is usually asymptomatic. Some infants may experience fussiness, decreased feeding, and refusal to feed. Older children may complain of a sore mouth, sour taste, difficulty in tasting food, or burning sensation.1


The diagnosis of oral candidiasis is often clinical, especially when the lesion is typical. Concomitant monilial diaper dermatitis may aid diagnosis. Potassium hydroxide wet-mount examination of swabs taken from the affected area or culture of the fungus with Sabouraud peptone-glucose agar may be performed. However, isolation of Candida in the absence of clinical correlation does not indicate active infection.3

Milk curd can be distinguished from pseudomembranous candidiasis by the ease with which it is removed from the oral mucosa. Other differential diagnoses include oral mucositis from chemotherapy, burns of the oral mucosa, oral leukoplakia, and other oral fungal infections.1


Oropharyngeal candidiasis, if severe, can impair speech, feeding, taste, and quality of life.5 Occasionally, the infection can spread to the esophagus.8 Rarely, systemic dissemination and fungemia may result in susceptible and debilitated persons.3


Any predisposing factors need to be removed when possible. In immunocompetent children, oral candidiasis usually responds well to oral nystatin suspension or clotrimazole troches applied to lesions.10 How-ever, troches are not recommended in infants.10 Treatment duration is usually 2 weeks but should continue 2 to 3 days beyond resolution of the lesion.1

Treatment with fluconazole, miconazole, itraconazole, or ketoconazole can increase cure rates and can be prescribed for recalcitrant or recurrent infections and for immunocompromised patients.1,10 However, the associated costs with these agents are considerably higher.5,10