Oral thrush appears as creamy white, slightly raised patches on the tongue, inner cheeks, or other soft surfaces inside the mouth. The patches have a distinctive cottage cheese-like texture and can usually be wiped off, revealing red or raw-looking tissue underneath. If you’re checking your mouth (or your baby’s) and see something matching that description, thrush is a strong possibility.
The Classic White Patches
The hallmark of oral thrush is white, curd-like lesions that sit on top of the tissue rather than blending into it. They most commonly show up on the tongue and the insides of the cheeks, but they can also appear on the roof of the mouth, the gums, the tonsils, and the back of the throat. The patches may be small and scattered or merge into larger areas of white coating.
One of the most reliable ways to tell thrush apart from other white spots in the mouth is the wipe test. If you gently rub the white area with a clean cloth or gauze, thrush patches come off relatively easily. What’s left behind is a reddish, sometimes slightly bleeding surface. This is a key distinction: white spots from other conditions like leukoplakia (a precancerous change) or lichen planus can’t be wiped away. If the white coating stays put when you try to remove it, it’s likely something other than thrush.
Thrush Without White Patches
Not all oral thrush looks white. There’s a red form that skips the cottage cheese appearance entirely. Instead, you’ll see smooth, red, irritated areas, most often on the top surface of the tongue, the palate, or the inner cheeks. On the tongue specifically, these red patches look like areas where the tiny bumps (papillae) have worn away, leaving a flat, glossy surface.
This red form is common in people taking antibiotics. The mouth feels sore and raw, and the tongue may look unusually smooth and inflamed. Because there are no white patches, this version of thrush often goes unrecognized or gets mistaken for a general irritation.
Cracking at the Corners of the Mouth
Thrush can also affect the skin just outside the mouth. When the yeast infects the corners of the lips, it causes a condition called angular cheilitis: red, cracked, sometimes crusty splits right at the angles where your upper and lower lips meet. The area gets dry, sore, and may sting when you open your mouth wide or eat acidic foods. Saliva that collects in the corners creates a moist environment that keeps the yeast thriving, which is why these cracks can be stubborn to heal on their own.
How It Looks in Babies
Thrush is especially common in newborns and young infants. In babies, it shows up as creamy white spots or patches on the tongue, gums, roof of the mouth, or inner cheeks. You may also notice a white film across your baby’s lips. Unlike milk residue, which wipes off easily after a feeding, thrush patches resist gentle wiping and stay in place.
Babies with thrush often become fussy during breastfeeding or bottle feeding, pulling away or refusing to latch. Some develop a persistent diaper rash at the same time, since the same yeast can pass through the digestive system and irritate the skin. If your baby has white mouth patches along with an unexplained rash that won’t clear up, thrush in both locations is a likely explanation.
What It Feels Like
Beyond what you can see, thrush produces a set of sensations that help confirm what you’re dealing with. The mouth often feels cottony or dry. You may notice a loss of taste or an unpleasant taste that lingers. Eating and swallowing can be painful, especially with hot, spicy, or acidic foods. The tissue under and around the patches may feel tender or burn slightly, even when you’re not eating.
In more severe cases, particularly in people with weakened immune systems, the infection can spread down into the esophagus. When that happens, swallowing becomes noticeably painful and it may feel like food is getting stuck in your throat or chest.
Who Gets It and Why
Thrush is caused by an overgrowth of Candida, a yeast that normally lives in small amounts in your mouth. It becomes a problem when something disrupts the balance. Antibiotics are a common trigger because they kill off bacteria that normally keep yeast in check. Inhaled corticosteroids for asthma are another well-known cause: the steroid residue that settles in the mouth suppresses the local immune response and creates conditions the yeast loves.
If you use a steroid inhaler, rinsing your mouth with water or brushing your teeth after every use significantly reduces your risk. Keeping the inhaler device clean between uses also helps. Other risk factors include diabetes, a weakened immune system, dentures that don’t fit well, dry mouth, and smoking.
How It’s Treated
Mild to moderate oral thrush is treated with an antifungal gel or liquid that you apply directly inside the mouth. Treatment typically lasts 7 to 14 days. You swish or hold the medication in your mouth before swallowing, which allows it to coat the affected areas. Most people see improvement within a few days, though finishing the full course matters to prevent the infection from bouncing back.
For severe or recurring cases, especially in people with compromised immune systems, a healthcare provider may prescribe a systemic antifungal taken by mouth in pill form. Thrush that has spread to the esophagus always requires this stronger approach rather than topical treatment alone.