Oral candidiasis, also called oropharyngeal candidiasis and commonly known as oral thrush, is a common cause of infection of the oral mucous membranes by Candida species, especially Candida albicans. It is common during infancy when the immune system and immune responses are developing.

Transmission of infection occurs either at the time of delivery during passage through the vaginal canal or after delivery during handling or breastfeeding by the mother. Neonates that become infected at the time of delivery usually present with symptoms between 2 and 4 weeks of age. Infection later on in infancy can result from repeated use of antibiotics or occur in infants with human immunodeficiency virus (HIV) infection or a primary immunodeficiency syndrome.

Oral candidiasis appears in a number of clinical forms. The most common form is the pseudomembranous variety: white plaque formation typically appears on the tongue, lips, inner surface of the cheeks, and palate and can leave behind punctate bleeding and patches of reddened mucosa when scraped.

Candida at the corners of the mouth is known as angular cheilitis or perlèche. Crusting, small ulcers, or fissures can be present at the angles of the mouth.

The infant may be symptomless or may be generally irritable and show a decreased willingness to feed.

Related topics: Neonatal candidiasis, Diaper dermatitis candidiasis, Angular cheilitis, Congenital candidiasis