Cracked corners of the mouth, known medically as angular cheilitis, heal best when you address two things at once: keep the area dry and protected, and treat whatever is causing the skin to break down. Most mild cases clear up within one to three weeks with the right approach. Left alone, though, the cracks tend to reopen every time you eat, yawn, or talk, trapping the condition in a frustrating cycle.
Why the Corners of Your Mouth Crack
The skin at the corners of your mouth sits in a natural crease where saliva collects. When that moisture lingers, it softens and weakens the skin, creating tiny fissures. Once the skin is broken, fungi (most commonly Candida, the same organism behind oral thrush) and bacteria like Staphylococcus move in, turning a small crack into an inflamed, sometimes crusty sore. In many cases, both organisms are present at the same time.
Several things make this moisture buildup more likely:
- Lip licking or drooling during sleep, which keeps saliva constantly pooled at the corners
- Ill-fitting dentures, which can change the way your lips close and create deeper skin folds where moisture sits
- Braces or other dental appliances that alter your bite temporarily
- Aging-related skin changes, as the loss of facial volume deepens the creases around the mouth
Cold, dry weather can kick things off too. You lick your lips because they feel dry, the saliva evaporates and leaves them drier than before, and the cycle accelerates.
Nutritional Deficiencies That Play a Role
Up to 25% of angular cheilitis cases are linked to deficiencies in iron or B vitamins. That’s a significant share, and it explains why some people find their cracks keep coming back no matter what they put on them. If the underlying deficiency isn’t corrected, topical treatments only offer a temporary fix.
The nutrients most closely tied to mouth corner cracks include:
- Riboflavin (vitamin B2), whose deficiency also causes a swollen, magenta-colored tongue and sensitivity to light
- Vitamin B12 and folate, which can also cause fatigue, tingling in the hands or feet, and a sore tongue
- Iron, whose deficiency shows up as unusual tiredness, brittle nails, and sometimes difficulty swallowing
- Zinc, which can also cause hair thinning, diarrhea, and slow wound healing elsewhere on the body
If you’re getting cracks repeatedly and you also notice any of those accompanying symptoms, a simple blood test can check your levels. Vegetarians, vegans, people with celiac disease or Crohn’s, and those who have had weight-loss surgery are at higher risk for these deficiencies.
How to Treat the Cracks at Home
The single most effective thing you can do right now is create a moisture barrier. Applying a thick layer of petroleum jelly or a zinc oxide ointment to the corners of your mouth keeps saliva from reaching the damaged skin. Zinc oxide is especially useful here because it’s anti-inflammatory, mildly antibacterial, and forms a sturdy physical barrier against moisture. Apply it before bed and after meals, when saliva exposure is highest.
At the same time, you need to stop the habits that keep the area wet. That means consciously avoiding licking your lips, even when they feel dry. Use a plain, fragrance-free lip balm on the lips themselves, and reserve the thicker barrier ointment for the corners specifically. If you drool during sleep, sleeping on your back can help reduce moisture contact.
For mild cases with just some redness and minor cracking, a barrier ointment alone may be enough. You should notice improvement within a few days and full healing within one to two weeks.
When You Need an Antifungal
If the cracks are deep, crusted, or have been present for more than a week without improvement, a fungal infection is likely involved. Over-the-counter antifungal creams designed for yeast infections (containing clotrimazole or miconazole) work well when applied to the corners two to three times daily. Continue using them for a few days after the skin looks healed to prevent a quick relapse.
Sometimes both a fungal and bacterial infection are present, which is why stubborn cases may need a prescription combination cream that targets both. If an OTC antifungal hasn’t made a noticeable difference after a week, that’s a sign to get it looked at.
Preventing It From Coming Back
Angular cheilitis is notorious for recurring. Once the skin at the corners has cracked and healed, it’s slightly more vulnerable to cracking again. Prevention is really about controlling the conditions that let it start in the first place.
Keep a small tube of petroleum jelly or zinc oxide ointment handy, especially in winter, and apply it to the corners of your mouth before bed as a routine. This is particularly helpful if you breathe through your mouth at night or wear a CPAP machine, both of which dry out and then over-moisten the lip area in cycles. If you wear dentures, having them checked for proper fit can eliminate the excess skin folding that traps saliva. Even natural teeth wear down over time, changing your bite enough to deepen those corner creases.
On the nutrition side, eating a diet rich in B vitamins, iron, and zinc covers the most common deficiency triggers. Good sources of riboflavin include eggs, dairy, almonds, and fortified cereals. Iron comes from red meat, lentils, and spinach. Zinc is abundant in shellfish, pumpkin seeds, and chickpeas. If you suspect a deficiency, supplementation works, but it’s worth getting tested first so you know what you’re actually low in rather than guessing.
What Persistent Cracks Can Signal
Cracks that last more than two to three weeks despite proper treatment sometimes point to something beyond a local skin problem. Diabetes makes people more susceptible to Candida overgrowth, and persistent angular cheilitis can be one of its early visible signs. Inflammatory bowel diseases like Crohn’s can cause it too, because they interfere with nutrient absorption. Immune suppression from medications or illness is another common driver of cases that won’t resolve easily.
If your cracks keep returning every few weeks, or if they’re severe enough to bleed and make eating painful, it’s worth investigating those deeper causes rather than continuing to treat the surface alone. A doctor or dermatologist can swab the area to identify whether Candida, bacteria, or both are involved, and can order bloodwork to check for nutritional gaps or underlying conditions that need their own treatment.