Oral thrush, or oral pseudomembranous candidiasis, is a superficial mucous membrane infection that affects approximately 2–5% of normal newborns. Infants acquire Candida from their mothers at delivery and remain colonized.
Thrush may develop as early as 7–10 days of age. The use of antibiotics, especially in the 1st year of life, may lead to recurrent or persistent thrush. The plaques of thrush invade the mucosa superficially and may be found on the lips, buccal mucosa, tongue, and palate. Removal of plaques from these surfaces may cause mild punctate areas of bleeding, which helps to confirm the diagnosis.
Thrush may be asymptomatic or may cause pain, fussiness, and decreased feeding. It is uncommon after 12 mo of age but may occur in older children treated with antibiotics. Persistent or recurrent thrush with no obvious predisposing reason, such as recent antibiotic treatment, warrants investigation of an underlying condition such as diabetes mellitus or immunodeficiency, especially vertically transmitted HIV infection.
Treatment of mild cases may not be necessary. When treatment is warranted, the most commonly prescribed antifungal agent is nystatin. Therapeutic agents in decreasing order of efficacy include miconazole gel, amphotericin B suspension, gentian violet, and nystatin suspension. Clotrimazole troches may also be effective, although clinical studies are lacking. Miconazole gel is currently unavailable in the United States. For recalcitrant or recurrent infections, a single dose of fluconazole may be useful. Fluconazole has been shown to be safe in premature infants, and effective in a single dose for HIV-infected children with oral candidiasis. In breast-fed infants, simultaneous treatment of infant and mother with topical nystatin or oral fluconazole may be indicated.