Thrush is an infection of the mouth that is extremely common in children under the age of six months. It also can affect older babies and toddlers. In addition, nursing mothers are at risk for thrush when it is passed between them and their babies during breastfeeding.

A fungus called Candida albicans – more commonly known as yeast – causes the majority of oral thrush infections. Small amounts of fungi are always present in the mouth, skin and digestive tract. However, certain factors such as illness, medication use or high glucose (blood sugar) levels can alter the environment inside the mouth or throat, causing Candida albicans to multiply rapidly and invade surrounding tissues.

When this occurs, thrush typically causes symptoms such as creamy, white, curd-like lesions on the tongue and inner cheeks. It can also affect the gums, tonsils, palate and lips. Babies with thrush may also experience diaper rash as the fungus moves through the digestive tract. Mothers who breastfeed a child with thrush may experience infection of the nipple, which results in red, cracked and sore nipples, an intense burning pain in the nipples during and after nursing, or stabbing pains deep within the breast.

Parents who discover white patches on their baby’s tongue or cheeks should use a clean washcloth to wipe them away. Parents are urged to bring the baby to a pediatrician if the patches are not easily removed or if they leave raw tissue underneath. Oral thrush has a distinct appearance and can typically be diagnosed by a physician through visual inspection alone.

Massaging the mouth with plain yogurt containing live cultures may help mild cases of thrush. These cases may disappear within 24 to 48 hours of treatment. Moderate to severe oral thrush is often treated with antifungal medications, which impede the growth of yeast. Infants are almost always treated with topical antifungals if medication is used.