Cracks in the corners of your mouth are usually angular cheilitis. It is a common condition that causes redness, soreness, and splitting at one or both corners of the lips. The most frequent causes are a fungal or bacterial infection, a lack of certain vitamins, or constant lip-licking and dry skin.
What Exactly Is Angular Cheilitis?
Angular cheilitis is the medical name for this condition. It is inflammation of the corners of the mouth, where the upper and lower lips meet. The skin there is delicate and folds inward, creating a small crease. That crease traps moisture easily, which makes it a perfect spot for infections to grow.
It is not cold sores. Cold sores are caused by the herpes simplex virus and usually appear as small, fluid-filled blisters. Angular cheilitis is not a virus. It is an inflammatory reaction, often with an added yeast or bacterial infection in the fold of skin.
What Causes Cracks In The Corner Of Your Mouth?
The most common cause is a fungal infection, specifically a yeast called Candida albicans. This yeast lives naturally on your skin. When the corner of the mouth stays wet, the yeast multiplies and causes an infection. Saliva collects in the crease, especially if you have deep smile lines or wear dentures that change how your lips meet.
Bacterial infections are the second most common cause. The same bacteria that cause impetigo or strep throat can infect the corners of the mouth. Some people have both a yeast and a bacterial infection at the same time.
Beyond infections, the condition can start with simple dryness. Chapped lips, cold weather, or constant licking can break the skin. Once the skin cracks, yeast or bacteria move in and keep the sore from healing.
Nutritional Deficiencies That Cause Sore Mouth Corners
Low levels of certain vitamins and minerals can cause these cracks. The most common deficiency linked to angular cheilitis is a lack of B vitamins, especially riboflavin (vitamin B2). Low iron levels can also cause it, as can low zinc.
These nutrients help your skin repair itself. When they are low, the skin at the corners of your mouth becomes weak and splits easily. The cracks then get infected, which makes the problem worse.
If you eat a mostly balanced diet, a deficiency is less likely but still possible. People with digestive conditions that affect nutrient absorption, like celiac disease or Crohn’s disease, are at higher risk. Older adults are also more prone to low B vitamins and iron.
Why Dentures and Tooth Loss Play a Role
Dentures are a major cause of angular cheilitis in older adults. When dentures do not fit well, the mouth closes at a different angle. This creates a deeper fold at the corners of the lips. Saliva pools in that fold, keeping the skin wet and irritated.
Tooth loss without dentures can cause the same problem. The lips collapse inward, making the skin fold deeper. This is why angular cheilitis is much more common in people who wear dentures or have missing teeth.
If you wear dentures, keeping them clean is important. The yeast that causes angular cheilitis often lives on the denture surface. Simply treating the skin without cleaning the denture usually leads to the cracks returning.
Other Triggers: Lip Licking, Allergies, and Dry Skin
Constant lip licking is a common trigger. Saliva contains digestive enzymes. When saliva sits on the skin for long periods, it breaks down the skin’s protective barrier. This leaves the corners raw and cracked.
Allergic reactions can also cause the condition. Lip balms, toothpaste, lipstick, and even certain foods can irritate the skin at the corners of the mouth. This is called allergic contact dermatitis. If the cracks appeared after you started using a new product, that product may be the cause.
Dry skin from cold weather or indoor heating can start the process. When the skin is dry, it loses elasticity. The natural movement of your mouth when you talk or eat can then cause tiny splits at the corners.
How To Treat Cracks At The Corner Of Your Mouth
Treatment depends on the cause. For a simple dry-skin case, a thick barrier ointment like petroleum jelly can help. Apply it at night and throughout the day. Keeping the area moisturized stops the skin from cracking further.
For a yeast infection, an antifungal cream is the standard treatment. Clotrimazole and miconazole are common options available over the counter. These creams kill the yeast and allow the skin to heal. Apply them as directed on the package, usually two to three times daily.
If the cause is bacterial, an antibiotic ointment may be needed. Many combination creams contain both an antifungal and an antibacterial agent. These are often the best first choice because many cases involve both types of infection.
For cracks caused by vitamin deficiency, supplements can help. If you suspect low B vitamins or iron, ask your doctor for a blood test before starting supplements. Taking extra vitamins when you do not need them does not help and can sometimes cause problems.
See a doctor if the cracks do not improve after two weeks of home treatment. Also see a doctor if the area swells, oozes, or becomes very painful. These signs may indicate a more serious infection that needs prescription treatment.
How To Prevent Angular Cheilitis From Coming Back
Prevention focuses on keeping the corners of your mouth dry and protected. After brushing your teeth or eating, gently pat the corners of your mouth dry with a tissue. Do not rub, as rubbing irritates the skin.
Stop licking your lips. If you have a habit of licking, use a barrier balm that tastes unpleasant to help break the habit. Applying petroleum jelly at night creates a protective layer while you sleep.
If you wear dentures, remove them at night. Clean them thoroughly with a denture cleaner. This removes yeast and bacteria that can reinfect the corners of your mouth.
Protect your lips from harsh weather. Use a lip balm with SPF during the day. In winter, cover your mouth with a scarf when outside. Keeping the skin hydrated prevents the initial cracks that lead to infection.
When Cracks Are A Sign Of Something Else
Most cases of angular cheilitis are not serious. But persistent cracks that do not heal can sometimes point to an underlying health condition. Diabetes, immune disorders, and certain skin conditions like eczema or psoriasis can all cause chronic angular cheilitis.
In rare cases, a sore at the corner of the mouth that does not heal could be a form of skin cancer. This is uncommon, but it is a reason to take persistent cracks seriously. If a crack lasts more than a few weeks despite treatment, get it checked by a dermatologist.
Do not ignore cracks that keep returning. If you treat the infection but it comes back within a few weeks, there is likely an underlying cause that needs addressing. That could be a nutritional deficiency, a poorly fitting denture, or an undiagnosed health condition.
Frequently Asked Questions
Are cracks in the corner of your mouth a sign of a vitamin deficiency?
Yes, low levels of B vitamins, iron, or zinc can cause these cracks. A blood test can confirm whether a deficiency is the cause.
Can I use hydrocortisone cream on cracked mouth corners?
Only if a doctor recommends it. Hydrocortisone reduces inflammation but does not treat the underlying yeast or bacterial infection, and it can make an infection worse.
How long does angular cheilitis take to heal?
With the right treatment, most cases improve within one to two weeks. If there is no improvement after two weeks, see a doctor.
Is angular cheilitis contagious?
It is not considered highly contagious. The yeast and bacteria that cause it are already present on most people’s skin, but direct contact with an active sore can transfer the infection.
