What is it?
Angular cheilitis is the redness, cracking, weeping and crusting that develops at the two corners where the lips meet. It can be on one side or on both. Because opening the mouth, yawning or smiling reopens the crack, the trouble carries on and healing drags out.
Although the name suggests dryness, the underlying problem is most often too much moisture. When a lasting fold forms at the corner, saliva collects there and seeps out. Skin that stays wet all the time thins and cracks, and it becomes easier for microbes to settle. Assessments have reported that a yeast fungus is most often present together with certain skin bacteria.
This is why angular cheilitis keeps coming back when it is treated as a skin problem alone. Unless the reason for the fold at the corner, any thrush inside the mouth and any deficiency related to diet are considered together, the sore closes and then opens again. It is told apart from a cold sore by where it sits: a cold sore starts on the red border of the lip with fluid-filled blisters, while angular cheilitis stays at the corner and does not blister.
Signs
You will not necessarily have all of these at once.
Why does it happen?
- 01
A lasting fold at the corner and pooling saliva
Missing teeth, worn teeth or a denture that has settled lower reduce the vertical height of the bite and fold the corners of the lips inwards. Saliva collecting in this fold keeps the skin wet all the time and sets the stage for the surface to break down.
- 02
Fungus and bacteria present together
In the damp setting at the corner, yeast fungus and skin bacteria multiply easily. In denture wearers the fungus is most often present on the palate as well; if only the corner is treated, the problem is fed again from the reservoir inside the mouth.
- 03
Iron, B12 and folate deficiencies
These deficiencies slow the renewal of the skin and of the lining of the mouth. Where cracked corners go together with frequent aphthous ulcers, a smooth red tongue or tiredness, a blood test comes into consideration; the decision on testing and treatment rests with your doctor.
- 04
Habits, dryness and some medicines
Licking the lips, sucking the corners, breathing through the mouth and a dry mouth keep the problem going. Some medicines that make the skin markedly dry, and some skin conditions, can also make cracking at the corner more likely.
How does it progress?
- 1
The red stage
At first there is mild redness and tightness at the corner, and the skin looks shiny and moist. There is no crack yet; opening the mouth wide feels uncomfortable.
- 2
Cracking and crusting
A line-shaped crack opens at the corner and crusts over. Opening the mouth tears the crack again, so healing starts and stops. Burning and stinging become noticeable at this stage.
- 3
Deepening and spreading
The crack deepens, the redness widens beyond the corner, and weeping and bleeding may be seen. This appearance most often suggests that there is a source of thrush inside the mouth as well.
- 4
The recurring form
The sore closes and, a few weeks later, opens again in the same place. This cycle shows that the underlying bite problem, or a cause elsewhere in the body, has not been dealt with.
How is it treated?
In the clinic, the first step is to work out which heading the cause falls under. How the corners of the lips sit in relation to the height of the bite is assessed, the fit and the vertical height of any denture are reviewed, and the mouth is checked for signs of thrush. Without this assessment, any improvement gained from products applied to the corner alone can be expected to be short-lived.
The part of the treatment that takes place inside the mouth is within the field of dentistry. Replacing missing teeth, building worn teeth back up in height, or relining or remaking a denture reduces the fold at the corner. If you wear a denture, the habit of taking it out at night and cleaning it mechanically is established; if there is a reservoir of thrush on the palate, it is dealt with together with a medicine for the mouth that your dentist considers suitable.
Medicines to be applied to the corner are chosen by the clinician who assesses you. Which part of the picture stands out, the fungus, the bacteria or the inflammation, changes what the treatment contains; for that reason, using creams containing a steroid on your own judgement and over a long period is not advised. A crack that has not settled within a few weeks despite the right approach, that persists on one side only or that becomes firm is assessed again.
- If the crack has not closed for several weeks and persists on one side only
- If the area at the corner is becoming firm or raised, or bleeds on its own
- If the redness is spreading towards the cheek and swelling is being added
- If a widespread white layer, burning and a change in taste have also appeared inside your mouth
How is it prevented?
- Keep the corners of your lips dry through the day; licking and sucking them delays healing.
- Take your denture out every night and clean its surface mechanically with a brush.
- Have your missing teeth replaced; as the height of the bite drops, the fold at the corner deepens.
- If the cracking keeps coming back, ask your doctor to check your iron and B12 levels.
Frequently asked questions
- Is angular cheilitis a cold sore?
- No, the two are different. A cold sore is caused by a virus; it starts with tingling on the red border of the lip, forms small fluid-filled blisters and heals by crusting over, and it is infectious. Angular cheilitis stays at the corners of the lips, does not blister and is not treated as an infectious condition. Where it sits, and whether there are blisters, are the practical basis for telling them apart.
- Is a moisturiser enough on its own?
- A protective layer can stop the crack reopening to some extent and can bring relief. It does not, however, remove the moisture and the microbes at the corner. When the real cause, such as the height of the bite, the fit of a denture or a reservoir of thrush inside the mouth, is not dealt with, the sore can be expected to come back.
- Is it infectious, will my family catch it?
- Angular cheilitis itself is not treated as an infectious condition; it is not something passed on by sharing a towel or a glass. Even so, the fungus multiplying at the corner can settle inside the same person's mouth and on the surface of their denture. That is why treatment is planned to cover not only the corner but the inside of the mouth as well.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.