Oral thrush: the good, the bad, the treatment plan

Most women will experience a vaginal yeast infection at some point in their lives. But did you know that you can get yeast infections on many different parts of your body, including your mouth? When this happens, it’s known as thrush. And, it’s not just women who suffer: new babies are most likely to be affected. Thrush is easily treatable, but if you don’t know what to look for, it can make both you and your baby miserable. 

What is thrush and what causes it?

No matter how clean you keep yourself, your body still ends up playing host to a huge number of microscopic organisms — including yeast. Yeast is found on most healthy people  and doesn’t normally cause any issues. But when you have an overgrowth of yeast, you end up with a yeast infection. The yeast strain Candida Albicans is the most common cause of yeast infections, as it thrives in warm, moist environments. It can produce infections ranging from vaginal yeast infections to fungal infections in your nail beds to thrush.

What causes oral thrush in babies?

Your baby can pick up thrush in a variety of ways, which can make it tricky to prevent. If you have a vaginal yeast infection when you give birth, your baby can pick it up as they exit the birth canal — which is one of the reasons thrush is most common in infants under six months. Since breastfeeding exposes your nipples to damp, warm conditions on a regular basis, they’re susceptible to yeast infections, especially if your nipples crack or you don’t use fresh breast pads regularly. And because little ones are in frequent contact with your nipples, it’s easy for the yeast infection to colonize your baby’s mouth. Candida Albicans thrives in babies’ mouths so well because they have weaker immune systems and their mouths are so warm and damp. Medications can also cause thrush as a by-product: antibiotics can kill off the “good” bacteria that normally keeps Candida in check. And steroids, such as those given for common baby illnesses like croup, can do this as well. 

Apart from babies, thrush also disproportionately affects the elderly, as well as AIDS and cancer patients — all groups with weakened immune systems. That’s why risk factors for thrush include diabetes, being immunocompromised, or having recently taken antibiotics. Sometimes, the hormonal changes of pregnancy also cause oral thrush; treatment is effective and safe, even while pregnant.

Is thrush contagious?

Thrush isn’t contagious under most circumstances — it doesn’t spread through coughing, sneezing, or kissing (usually), for example. Don’t worry about keeping your infant or child home from daycare, as thrush won’t spread to healthy skin. In some cases, however, as with breastfeeding mothers and their nursing babies, thrush is contagious, as it can be transmitted back and forth between the mother’s breasts and the baby’s mouth. 

Newborn thrush vs. milk tongue

Thrush is usually visible as whitish patches on your baby’s tongue. This shouldn’t be confused with “milk tongue,” which is just the traces of milk left on the tongue. Breastfed infants drink a lot of milk and they don’t produce much saliva until three months or so, so it’s normal for your baby to have traces of milk in their mouth much of the time. If you’re able to gently wipe this white residue away, if it appears only on the tongue, or if your baby has no other symptoms, it’s likely just milk tongue. But if you can’t wipe these white patches away, or if your baby is also exhibiting other symptoms of thrush, it’s time to check with a doctor.

Symptoms of oral thrush

• White patches that look like milk or cottage cheese on the inside of your baby’s mouth or on their lips that you can’t wipe away.
• Cracking in the corners of your baby’s lips.
• Shorter feeding periods, decreased appetite, or your baby frequently pulling off your breast.
• Increased crankiness or fussiness when your baby is nursing or using a pacifier.

If your baby has oral thrush, there’s a chance that mom also has nipple thrush. In this case you might notice that your nipples are:

• Pink and shiny
• Flaky
• Itchy

You might also experience stinging, or sharp, shooting pains while breastfeeding and/or pain between nursing sessions.

Diagnosing oral thrush

Your doctor will diagnose a case of thrush based on your description of symptoms. They will likely want to look at your baby’s mouth as well. Rarely, your doctor may want to take a scraping of one of the white patches to examine under a microscope.

How to treat thrush in babies

Thrush will sometimes go away on its own after a few days. But if either you or your baby is experiencing discomfort or your baby is eating noticeably less, see your doctor. They’ll likely prescribe an antifungal medication to treat your child’s oral candidiasis (another name for thrush). Until recently, gentian violet was often prescribed as an oral thrush treatment for babies, either alone or in addition to other antifungals. However a recent alert by Health Canada warns Canadians to stop using all products containing gentian violet, as it may increase your risk of cancer.

Make sure to tell your doctor about any other symptoms your baby may have, such as diaper rash, as your doctor will likely want to treat that differently. If both you and your child have an infection, it’s imperative you both receive treatment. Otherwise you risk re-infecting one another. Your doctor will advise you on whether you need an oral anti-yeast medication for yourself, or if you can simply treat your nipples with an over-the-counter (OTC) yeast infection cream. They should also advise you on how long to wait to breastfeed after treating your nipples with that cream.

Treating thrush in toddlers is no different than with a baby, though you might have more trouble giving an older child an oral thrush medication! 

Why do I keep getting thrush?

Yeast is often able to enter the mother’s nipple because of a break in the skin. This often happens with an improper latch or an undiagnosed tongue tie. Thrush in breastfeeding women may continue to return because it hasn’t been treated properly, or because the underlying issues that caused it haven’t been addressed. If you find yourself with recurrent thrush, it’s important to speak to a lactation consultant (LC) or a physician to figure out what else is going on. Share your health history with your doctor to rule out any underlying health issues (such as diabetes). This is true for your baby too, as resistant or recurring oral thrush could be a sign that their immune system is wrestling with an as-yet undiagnosed health issue.

Making sure your baby has a proper latch from the beginning of your breastfeeding journey can help limit nipple cracking. As well, using the right supplies can help prevent thrush: plastic-lined nursing pads and improperly sterilized bottles and pacifiers provide a warm, moist environment for yeast to thrive in, so make sure anything touching your breasts or going into your baby’s mouth is clean, dry, and in good shape. Pain during breastfeeding isn’t normal — plus, accompanying changes in your baby’s behaviour often signal that something is wrong. If you have any concerns, don’t hesitate to speak with a doctor.