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.

Thrush is a type of mouth infection caused by an overgrowth of a fungus called Candida, more commonly known as yeast. It may also be called oral thrush, oropharyngeal candidiasis or OPC. Newborns are among the groups at the highest risk for thrush. In most cases, thrush is easily treatable and is not viewed as a serious health threat.

There are several types of Candida. However, a variety called Candida albicans causes the majority of oral thrush infections. Small amounts of these single-celled fungi are always present in the mouth, skin and digestive tract. Certain factors, such as illness, medications 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. An overabundance of this fungus causes symptoms of thrush.

Oral thrush can affect anyone, but is extremely common in children under the age of six months. It also can affect older babies and toddlers. Usually, oral thrush is not passed from person to person through casual contact. However, it may be transmitted between child to mother through breastfeeding. If an infant who is breastfeeding has thrush, the mother should use antifungal cream on her nipples to prevent further spreading of the disease in the infant.

Thrush can also be transmitted when a child with a developing immune system shares items contaminated with the Candida fungus. Examples of such items include pacifiers or toys that have been in oral contact with an infected child. 

Thrush is also more prevalent in:

• People with uncontrolled diabetes mellitus
• Individuals with compromised immune systems, particularly those with HIV or AIDS

Left untreated, symptoms of oral thrush may become persistent and painful. It can spread to the esophagus (esophagitis), the skin or the vagina (yeast infection). In rare cases, invasive candidiasis (a condition characterized by infections in the organs and bloodstream) may occur, affecting the:

• Heart (endocarditis)
• Brain (meningitis)
• Joints (arthritis)
• Eyes (endophthalmitis)

A yeast called Candida albicans causes thrush. Yeast is a type of fungus that can be found in a person’s intestines, mouth or skin. The body normally regulates the amount of yeast it has, but in some cases yeast can grow uncontrolled.

Thrush is commonly found in infants during the first few months of life. Young children have less fully developed immune systems than adults, so their bodies are less able to control the normal balance of yeast and bacteria. Newborn babies sometimes develop thrush after birth when their mothers have vaginal yeast infections at the time of delivery. In addition, babies who take antibiotics may kill off the bacteria in their bodies that normally control yeast.

Nursing mothers who take antibiotics are also at increased risk for developing thrush. In addition, a baby with oral thrush can infect the mother’s nipple during breastfeeding. Pregnancy itself can also cause thrush because the higher levels of the hormones estrogen and progesterone alter the balance of bacteria in the woman’s mouth and vagina.

Certain diseases may increase the risk of thrush in children. For example, chronic mucocutaneous candidiasis are a group of rare disorders that typically affect children younger than age three. These disorders are marked by chronic Candida infection of the mouth, fingernails and skin of the scalp, trunk, hands and feet.

Additional factors that can increase the risk of thrush in a nursing mother or her child include a mother’s high sugar diet or low resistance to disease due to fatigue or other health issues.

Other factors which can increase the likelihood of developing oral thrush in general include:

• Diabetes mellitus
  
  
• HIV/AIDS and other diseases that weaken the immune system
  
  
• Cancer
  
  
• Mononucleosis and other viral infections
  
  
• Certain medications, such as antibiotics, corticosteroids, birth control pills and drugs to suppress the immune system
  
  
• Chemotherapy
  
  
• Dry mouth (xerostomia)
  
  
• Irritation from partial plates or dentures
  
  
• Old age
  
  
• Poor health
  
  
• Smoking

Oral thrush is common in newborn babies and may appear about two weeks to a month after birth, or any time in the first six months. In infants, its appearance is often mistaken for milk or formula on the tongue or inner cheeks. Infants may also experience cracked skin in the corners of the mouth, and creamy, white, curd-like lesions on the tongue and inner cheeks. Oral thrush can also affect the gums, tonsils, palate and lips.

Initially, thrush may be painless. However, if the condition progresses, many individuals experience discomfort, especially if the thrush has spread from the mouth to the palate or throat. Signs and symptoms of oral thrush can develop suddenly, and may become chronic. In severe cases, lesions may spread into the esophagus (which connects the mouth to the stomach), causing a serious condition called Candida esophagitis.

Babies with thrush may also experience diaper rash as the infection spreads through the digestive tract. This rash tends to be very red and well-defined, and may be raised. Sores in the rash may contain pus, and additional lesions may appear on the stomach, thighs and a boy’s scrotum.

Irritability is also common and is most prevalent during feeding due to the mouth pain caused by thrush. Babies who suddenly refuse to nurse may have thrush.

Nursing babies can pass thrush on to their mothers by infecting the nipple during breastfeeding. An infected nipple is likely to be red, cracked and sore, and the skin of the areola may be taut and shiny. The mother may feel an intense burning pain in the nipples during and after nursing, or stabbing pains deep within the breast. This pain can be very intense.

Other symptoms associated with thrush include:

• Redness and/or bleeding of skin when lesions are rubbed or scraped
• A burning sensation in the mouth and throat
• Constant bad taste in the mouth
• Difficulty tasting foods
• Low-grade fever
• Loss of appetite
• Presence of other illnesses
• General feeling of sickness

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. A physician can usually diagnose the condition by looking for the characteristic white lesions on the mouth, cheeks and tongue. When the physician gently brushes away these patches, it will typically reveal tender, reddened areas that may bleed lightly. Physicians unable to visually determine whether thrush is present may perform a KOH prep test (a microscopic examination of scrapings from the mouth) to confirm the diagnosis.

Parents of adolescents and older children with no known risk factors are instructed to seek medical care if their child develops thrush. The physician will compile a thorough medical history and perform a complete physical examination to identify whether the thrush was caused by an underlying condition, such as diabetes. 

Left untreated, thrush can spread into other regions of the body, causing serious complications, such as Candida esophagitis. This condition occurs when thrush extends into the esophagus (which connects the mouth to the stomach). Diagnosis of Candida esophagitis may require additional tests, including:

• Throat culture. The back of the throat is swabbed with sterile cotton and the micro-organisms are studied under a microscope.
  
  
• Endoscopy of the esophagus, stomach and small intestines. A flexible camera captures images of the lining of the esophagus and surrounding areas.
  
  
• X-rays of the esophagus. An image of the esophagus is produced with low doses of radiation.

All cases of thrush in mothers and children should be treated, particularly if the child is breastfeeding. Failure to adequately treat thrush may result in the mother and child repeatedly infecting and reinfecting each other during breastfeeding.

Mild thrush can often be treated by simply wiping a child’s mouth with a clean, moist cloth. In some cases, massaging the mouth with plain yogurt containing live cultures can also rid the area of thrush. Mild cases of thrush 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 when medication is necessary. In some cases, symptoms may appear to get worse for a day or two before they improve. It can take three to five days after treatment begins before symptoms disappear.

To treat babies, parents may use a dropper to apply medication to a cotton swab that is then applied to the front and sides of the baby’s mouth several times a day. In addition, parents can help their children heal faster by preventing them from using pacifiers until the mouth heals. An antifungal cream may also be prescribed to treat any associated diaper rash. Treatments are typically given until 48 hours after the child’s symptoms disappear.

Mothers whose nipples become infected may use a special antifungal cream that treats the condition but remains safe for breastfeeding babies. Mothers may want to switch to short, frequent feedings until their nipples are less painful.  

In older children and adults, mild cases of thrush can generally be cured with antifungal lozenges or mouthwashes. More severe infections, however, typically require oral antifungal medication (in pill form), which should be taken anywhere from 10 days to two weeks. Several steps can be taken to make eating less painful while the child waits for a thrush infection to subside. These include:

• Eating easy-to-swallow foods such as gelatin, ice cream and custard
  
  
• Drinking cold liquids and eating flavored ice or frozen juices
  
  
• Using a straw to consume liquids
  
  
• Rinsing the mouth several times a day with warm saltwater

Individuals with severely compromised immune systems, such as those with HIV or AIDS, may require even stronger medications. Individuals with recurrent thrush infections may notice diminished effectiveness of antifungal medications over time and should consult their physician if this occurs.

Thrush may be difficult to prevent completely because the fungus is so common. However, some measures may help prevent the condition in infants. Soaking bottle nipples and pacifiers daily in hot tap water that is at least 130 degrees Fahrenheit (54.4 degrees Celsius) is one method. Other tips for reducing the spread of thrush to infants include:

• Treat vaginal yeast infections during pregnancy, particularly during the last trimester.
  
  
• Do not reuse a bottle that has been left out for more than an hour after the baby has drunk from it.
  
  
• Boil all objects for 20 minutes after they have been in a baby’s mouth, or put them in the dishwasher.
  
  
• Change the baby’s diaper soon after it is wet to prevent yeast from growing.
  
  
• Breastfeed babies to help build their natural defense systems.
  
  
• Mothers can switch to a diet that is low in sugars, highly processed foods and yeast-containing foods (e.g., mushrooms) to minimize yeast growth.

Babies who take antibiotics for conditions such as ear infections may be at increased risk for thrush, because the medication can kill bacteria in the mouth needed to prevent thrush. Parents are urged to have their children rinse their mouths out after taking an antibiotic.

Preparing questions in advance can help patients and parents have more meaningful discussions with their physicians regarding their or their child’s treatment options. The following questions related to thrush may be helpful:

1. How can I find out whether or not I have a yeast infection during my last trimester of pregnancy? If I do, how should I treat it?
   
   
2. What signs should I look for that might indicate my baby has thrush?
   
   
3. If I spot signs of thrush in my baby, how should I try to treat it?
   
   
4. How long should I wait before bringing my child to the doctor for medical attention?
   
   
5. If my child is infected, do I need to undergo treatment even though I have not experienced any symptoms?
   
   
6. How and how often should I apply my child’s medication?
   
   
7. How long will our treatments last?
   
   
8. What should I do if our infections return?
   
   
9. What foods should I eliminate from my diet that might reduce the risk of thrush?
   
   
10. What other prevention steps can I take?
    
    
11. Will it help minimize thrush infections if I stop breastfeeding?