Cracks in the corners of your mouth are almost always a condition called angular cheilitis, an inflammatory skin problem that causes fissures, redness, crusting, and sometimes bleeding right where your lips meet. Most cases clear up within two to three weeks with the right treatment, but the key is targeting the actual cause, which is usually a combination of moisture buildup and infection.
What Causes the Cracks
The most common trigger is infection, typically by a type of yeast called Candida or by staph bacteria. Often both are present at the same time. Saliva pools in the creased skin at the corners of your mouth, creating a warm, damp environment where these organisms thrive. Anything that increases moisture in that area, like frequent lip licking, drooling during sleep, or wearing braces, raises your risk.
Nutritional deficiencies account for roughly 25% of all cases. Iron deficiency is the most frequent culprit, followed by deficiencies in several B vitamins: riboflavin (B2), niacin (B3), pyridoxine (B6), and B12. These nutrients play direct roles in maintaining healthy skin and mucous membranes, so when levels drop, the thin skin at the mouth corners is one of the first places to break down.
Poorly fitting dentures are another major factor. One study of denture wearers with angular cheilitis found that nearly 83% had lost vertical dimension in their bite, meaning the dentures allowed the jaw to close too far. That creates deeper skin folds at the corners of the mouth where saliva collects. If you wear dentures and keep getting cracks, the fit of your prosthesis is worth evaluating.
How to Treat It at Home
If the cracks are mild (just dry, slightly red, and not oozing), a barrier approach can work. Apply zinc oxide paste or plain petroleum jelly to the corners of your mouth twice a day. This blocks saliva from sitting on the skin and gives the tissue a chance to heal. A basic, unflavored lip balm applied regularly throughout the day helps too.
When the cracks look more inflamed, with redness, swelling, or white patches suggesting a yeast infection, an over-the-counter antifungal cream is the standard first step. Look for one containing clotrimazole or miconazole. Apply a thin layer to the affected area twice a day, morning and evening, covering both the crack and the surrounding skin. Most drugstores carry these in the athlete’s foot section.
While you’re treating the area, a few habits make a big difference:
- Stop licking your lips. Saliva feels soothing for a moment but evaporates quickly, leaving the skin drier and more irritated than before.
- Rinse after eating. Wash your face and mouth with plain water after meals and after brushing your teeth to remove any residue that could irritate the corners.
- Skip gum, hard candies, and tobacco. All of these increase saliva production and often contain flavoring agents that irritate broken skin.
- Keep the area clean and dry. Gently pat the corners of your mouth dry throughout the day, especially after drinking.
When You Need a Prescription
If home treatment hasn’t resolved the cracks after two to three weeks, the infection likely needs a stronger approach. A common clinical protocol combines an antifungal cream (clotrimazole) with an antibacterial ointment (mupirocin), mixed in equal parts and applied to the corners of the mouth twice daily. This covers both yeast and bacteria simultaneously, which matters because most persistent cases involve more than one organism.
For cracks that still haven’t healed after three weeks of combined antifungal and antibacterial treatment, a short course of a potent prescription steroid ointment may be added to calm the inflammation. This is typically mixed with the antifungal and antibacterial agents and used briefly, not as a long-term solution. Steroid creams on their own can actually worsen an underlying infection, which is why they’re reserved for stubborn cases and always paired with antimicrobial treatment.
Addressing the Underlying Cause
Treating the surface infection is only half the job. If the cracks keep coming back, something is feeding the cycle. For many people, it’s a nutritional gap. A blood test checking iron levels and B vitamins can identify whether a deficiency is contributing. Correcting low iron or B12 through diet or supplements often stops recurrences entirely.
If you wear dentures, getting them relined or replaced to restore proper bite height can eliminate the skin folds where moisture collects. Even people with natural teeth can develop deeper mouth corner creases as they age or if they lose teeth, so dental health plays a larger role than most people realize.
Chronic or recurrent angular cheilitis sometimes signals an immune system issue. People with diabetes, those on long-term steroid inhalers, and anyone with a weakened immune system are more prone to persistent yeast infections at the mouth corners. If your cracks keep returning despite good treatment, it’s worth investigating these possibilities.
Is It a Cold Sore Instead?
Angular cheilitis is often confused with cold sores, but the two look and feel quite different. Cold sores start as an itchy or painful spot that develops into small fluid-filled blisters, which eventually weep, scab, and heal. They can appear anywhere on or around the lips. Angular cheilitis stays strictly in the corners of the mouth and begins as dry, cracked, irritated skin rather than blisters. If your cracks started with a tingling sensation and developed into visible blisters before crusting over, that points more toward a cold sore, which is caused by the herpes simplex virus and requires antiviral treatment instead.
Angular cheilitis that progresses without treatment can develop into swollen, painful sores that bleed when you open your mouth wide. At that stage it can look more like a cold sore, but the location (always at the corners) and the absence of a blister phase are the distinguishing features.