What Causes Angular Cheilitis? It's Not Just a Vitamin Deficiency: Treatment That Works, by a Dermatologist
Angular cheilitis is inflammation at one or both corners of the mouth. The corners become red, dry, cracked or fissured and flaky, sometimes with oozing or crusting, and they sting when you open your mouth or smile. It is a common problem at any age and in any gender, and it is not contagious.
When people get angular cheilitis, what they have usually heard is 'vitamin deficiency', so they buy vitamin B supplements and apply petroleum jelly and wait. As dermatologists, we want to help you understand two things that sales blogs and general pages often leave out. First, most angular cheilitis is not caused by a vitamin deficiency alone. The most common cause is saliva that stays pooled at the corners of the mouth until the skin becomes inflamed, and then yeast or bacteria make it worse. Taking vitamins or applying petroleum jelly alone therefore often does not clear it. Second, many people cannot tell angular cheilitis from cold sores, even though the two are caused by different germs and treated differently. Telling them apart correctly from the start matters more than rushing to find a cream.
What is angular cheilitis?
Angular cheilitis is inflammation at the corners of the mouth, where the outer skin meets the lining inside the mouth. This area moves constantly when you eat, talk and smile, and it is also a spot where saliva collects easily, so it is a delicate area that often becomes inflamed.
Typical features include:
Redness, cracks or fissures at the corners of the mouth, which hurt more when you open wide
Flaking, a wet or soggy look, oozing or crusting in some people
A burning, tight or itchy feeling at the corners of the mouth
Often on both sides and symmetrical, although it can occur on one side only
Most angular cheilitis is not dangerous and improves when treated the right way. But if it is left to become chronic or is not treated according to its cause, it can spread into a wider infection or keep coming back and never fully clear.
What causes angular cheilitis?
Understanding the cause correctly is the key to treatment, because angular cheilitis does not have a single cause. It usually results from several factors together, and the most common starting point is
1. Saliva pooling at the corners of the mouth (the main cause people overlook)
When the corners of the mouth are often wet with saliva, the skin becomes soggy and irritated, like skin that has soaked in water for a long time. Habits that let saliva collect, such as lip licking, deep folds at the mouth corners, drooling during sleep, or the pursed lips of older adults, can all trigger it.
2. Secondary infection
When the skin at the corners is soggy and cracked, germs already living in the mouth take the opportunity to move in. The common ones are Candida yeast, the same organism that causes white patches in the mouth, and Staphylococcus aureus bacteria. Some people have both yeast and bacteria together. This is why petroleum jelly alone is often not enough: it does not deal with the germs.
3. Nutritional deficiency (one cause, not the whole story)
Lacking certain nutrients can genuinely cause angular cheilitis, but it is only one cause and not always the answer. The nutrients involved include iron, vitamin B2 (riboflavin), vitamin B12, folate and zinc. Importantly, if there is a true deficiency, especially of iron to the point of anemia, there is often an underlying reason that should be found, rather than simply buying vitamins to take on your own.
Other risk factors that make it easier to get or to recur
Ill-fitting dentures or tooth loss make the mouth corners droop and form deep folds that trap saliva, which is common in older adults
Poorly controlled diabetes and weakened immunity make fungal infection more likely
Inhaled steroid sprays or antibiotics make it easier for yeast in the mouth to grow
Sensitive skin or atopic dermatitis, and contact allergy, for example to toothpaste or certain cosmetics
Acne medicines in the vitamin A derivative group (isotretinoin), which cause dry, cracked lips
Smoking and rapid weight loss, which loosen the skin and deepen the folds at the mouth corners
How is angular cheilitis different from cold sores and other conditions at the mouth corners?
This is where people are most confused, because sores on the lips or mouth corners can come from several conditions that are treated differently. Telling them apart correctly saves you from wasting time on the wrong treatment.
Angular cheilitis is at the corners of the mouth, with redness, cracks, fissures and flaking. It is usually on both sides, it is not a blister, and it is not contagious.
Cold sores (Herpes simplex) usually appear as a cluster of clear blisters on the lips or the lip border (not only at the corners). A burning or itching feeling comes first, the blisters appear in a group and recur in the same spot, and they are contagious through contact or shared items.
Lip-lick dermatitis is a red, flaky rash in a ring around the mouth, commonly seen in children who lick their lips.
Impetigo (a bacterial skin infection) has honey-yellow crusts and spreads quickly, and it is common in children.
A simple way to tell angular cheilitis from cold sores is that angular cheilitis is a 'crack at the corner of the mouth', while cold sores are 'a group of clear blisters on the lip', and cold sores usually give early warning symptoms and recur in the same place. If you are still not sure, having a dermatologist examine it will give a definite answer, and in some cases further testing may be used to confirm the germ.
Why does it not go away with vitamins or petroleum jelly?
Many people have chronic angular cheilitis that keeps coming and going even though they have taken vitamins and applied petroleum jelly all along. The reason is that the treatment does not match the real cause.
If the cause is yeast or bacteria, petroleum jelly only prevents dryness and does not kill the germs, so the sore stays inflamed.
If the cause is saliva pooling from lip licking or deep folds at the mouth corners, the sore will keep returning as long as the licking continues or the folds are not addressed.
If the cause is ill-fitting dentures, poorly controlled diabetes or iron deficiency, applying medicine to the corners alone is not enough, and the underlying factor must be addressed as well.
Put simply, angular cheilitis is an end result that can come from several starting points. If the starting point is not found, treatment goes around in circles without ending. This is why doctors look for the cause before choosing a medicine.
When should you see a doctor for angular cheilitis?
Most angular cheilitis can be managed at home at first, but you should see a doctor in the situations below, because a mouth corner that will not heal is sometimes a sign of a deeper problem than it looks.
It is chronic or recurs often, with no improvement after several weeks of self-care
It is on one side only and will not heal, which should be examined by a doctor to rule out other causes
You have other physical symptoms such as paleness, tiredness or palpitations, which may point to anemia from iron deficiency
You have diabetes, weakened immunity or take immunosuppressive medicine, because infection is easier and spreads faster
Saliva constantly leaks from the mouth corners, or you wear dentures, which may need adjusting together with a dentist
It is spreading, has pus, is very swollen and red or comes with a fever
As doctors, we are not telling you this to alarm you, but because a mouth corner that resists treatment can be a useful clue about your overall health. Finding the cause helps far more than applying cream again and again.
The right way to treat angular cheilitis
The evidence-based principle is to treat according to the cause together with caring for the skin at the mouth corners, not using one formula for everyone. In general the treatment has these parts.
Protect the skin and reduce moisture. Apply an ointment or petroleum jelly to coat the corners and keep out saliva and irritation. In cases caused purely by saliva, this step alone may be enough.
Deal with the germs. If yeast is suspected, doctors usually give an antifungal cream (for example from the clotrimazole, miconazole or nystatin group). If bacteria are suspected, an antibacterial cream may be given. Sometimes a combination product that both kills germs and reduces inflammation is used.
Reduce inflammation. In very inflamed cases, a doctor may also give a mild topical steroid for a short period, but you should not keep using it on your own for long because of side effects on the skin in this area.
Treat the root cause. Stop licking the lips, have dentures adjusted with a dentist, keep diabetes well controlled, and if a true iron or vitamin deficiency is found, supplement as the doctor advises while also looking for the reason for the deficiency.
Follow up. Angular cheilitis treated for the right cause usually improves within a few days and clears within 1–2 weeks. If it does not improve as expected, go back and reconsider what the real cause is.
Please note that medicines should be chosen with a doctor or pharmacist. Guessing the germ wrong and applying the wrong type of medicine is a major reason why angular cheilitis does not heal.
What not to do with angular cheilitis
Do not lick your lips or mouth corners, even when they feel dry and tight, because the more you lick, the more soggy and inflamed the skin becomes.
Do not apply only vitamins or petroleum jelly and leave it to become chronic. If there is no improvement after two weeks, the cause is not just dry skin.
Do not buy strong steroid creams or antibiotics to apply on your own too freely, because they may let yeast grow more or make the skin thinner.
Do not pick at crusts or pull off flaking skin, which risks deeper sores and repeat infection.
Do not share items such as drinking glasses or lip balm until you are sure it is not a cold sore, because cold sores are contagious.
Preventing angular cheilitis from coming back
Because angular cheilitis tends to return when the original factors are still there, prevention matters as much as treatment.
Stop licking your lips, and apply lip balm or an ointment to coat the mouth corners when they feel dry.
Keep your mouth and dentures clean. If your dentures are loose or you have lost teeth, talk to a dentist about adjusting them to fit.
Keep any chronic conditions well controlled, especially diabetes.
Eat a balanced diet with enough iron and B vitamins from food such as meat, eggs, liver, leafy greens and beans.
Rinse your mouth after every use of an inhaled steroid spray.
Avoid smoking, which helps both your skin and your oral health.
When to see a dermatologist
If your angular cheilitis keeps coming back, does not improve with self-treatment, stays on one side for a long time, or you have a condition such as diabetes or weakened immunity, seeing a dermatologist will give you a clear answer. A doctor can tell angular cheilitis apart from cold sores and other rashes that look similar, find the true cause whether it is yeast, bacteria, pooled saliva, dentures or a nutritional deficiency, and choose treatment that targets it, so that it heals and does not return, instead of trying creams over and over without knowing the real reason.
At Siam Dermatology we always follow the same approach to skin problems: examine correctly first, then treat. If you have angular cheilitis that has not healed with self-care, or you are not sure it is angular cheilitis, we are glad to give advice through a dermatologist.
Frequently asked questions (FAQ)
What causes angular cheilitis?
The most common cause is saliva pooling at the corners of the mouth until the skin becomes inflamed, followed by Candida yeast or bacteria making it worse. Nutritional deficiency, such as iron, vitamin B2, B12, folate or zinc, is only one of the causes and not the only answer. Ill-fitting dentures, diabetes and lip licking are also common contributing factors.
Which vitamin or mineral is lacking in angular cheilitis?
If it is truly caused by a nutritional deficiency, it is usually related to iron, vitamin B2 (riboflavin), vitamin B12, folate and zinc. But not everyone with angular cheilitis is deficient in vitamins. If you suspect a true deficiency, especially of iron to the point of paleness, the reason for the deficiency should also be investigated, rather than just buying vitamins to take on your own.
How is angular cheilitis different from cold sores?
Angular cheilitis shows as redness, cracks and fissures at the corners of the mouth, usually on both sides, not a blister, and it is not contagious. Cold sores are a group of clear blisters on the lip or lip border, with burning or itching first, recurring in the same place, and they are contagious. If you cannot tell them apart yourself, have a doctor examine it.
What should I apply for angular cheilitis, and which medicine makes it heal?
It depends on the cause. If it is caused by saliva and dry skin, coating with an ointment or petroleum jelly to keep out moisture may be enough. But if there is yeast, an antifungal cream is needed, and if there are bacteria, an antibacterial cream is needed. Some people use a combination product that also contains an anti-inflammatory, so the medicine should be chosen by a doctor or pharmacist according to the cause, not guessed.
Can angular cheilitis go away on its own, and how many days does it take?
Mild cases that are cared for the right way usually improve within a few days and clear within 1–2 weeks. But if the cause is not addressed, it often returns. If there is no improvement after two weeks, see a doctor.
My angular cheilitis will not go away. What should I do?
It is often because the treatment does not match the cause, for example there is yeast but only petroleum jelly is applied, or lip licking continues, ill-fitting dentures are still worn, or iron deficiency or diabetes has not been addressed. See a doctor to find the true cause and treat it accurately.
Is angular cheilitis dangerous?
Most cases are not dangerous and can be cured. But if left chronic it may spread into a wider infection, and sometimes a mouth corner that does not heal is a sign of anemia from iron deficiency, diabetes or weakened immunity, which should be examined.
Is angular cheilitis contagious?
Angular cheilitis itself is not contagious, but the germs that make it worse, such as yeast, or cold sores that are sometimes hard to tell apart, may spread. So do not share personal items with others until you are sure it is not a cold sore.
Written by Dr. Patara Voravutinon, Dermatologist · Last reviewed June 29, 2026
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