Some people develop angular cheilitis because of fungal or bacterial infection.
Nutritional deficiencies can also contribute in certain cases, including deficiencies involving iron, vitamin B12, folate, or other B vitamins.
However, a cracked mouth corner does not automatically indicate a nutritional deficiency.
A person with a balanced diet may develop the condition because of saliva exposure or irritation, while someone with a deficiency may have other symptoms as well.
When Could It Be Related to an Underlying Health Problem?
Persistent or recurrent angular cheilitis can sometimes be associated with conditions that affect immunity, nutrition, or blood glucose regulation.
For example, diabetes can increase susceptibility to certain infections, including fungal infections, although angular cheilitis alone is not a reliable indicator of diabetes.
Iron deficiency anemia and some vitamin deficiencies may affect the skin and tissues around the mouth.
People with immune suppression or certain chronic illnesses may also be more vulnerable to persistent infections.
The important point is that these are possible associations, not conclusions that can be drawn from appearance alone.
If the condition repeatedly returns, fails to improve, or occurs alongside fatigue, unexplained weight loss, frequent infections, or other concerning symptoms, a healthcare professional may consider further evaluation.
How Is Angular Cheilitis Usually Managed?
Treatment depends on the underlying cause.
For mild irritation, reducing saliva exposure and protecting the affected skin may help.
A bland barrier ointment, such as plain petroleum jelly, can protect the area from moisture and friction. Avoiding lip licking and irritating cosmetic products may also be beneficial.
If a fungal or bacterial infection is present, a clinician may recommend a specific treatment.
Using an antifungal or antibiotic product without understanding the cause may be ineffective and can sometimes worsen irritation.
People should also avoid repeatedly applying strong steroid creams to the corners of the mouth without medical advice, particularly when infection is possible.
If the problem persists, the clinician may examine the mouth and surrounding skin, review medications and dental factors, and consider testing for nutritional deficiencies or other conditions when indicated.