Angular cheilitis (also called perlèche, cheilosis, or stomatitis) is a condition with deep cracks and splits at the corners of the mouth. If severe, the splits or cracks may bleed when the mouth is opened and a shallow ulcer or a crust may form.

Possible causes of angular cheilitis include:

• Infection. Fungal infections are the most common, but viral or bacterial infections can also occur.
• Nutritional deficiency of vitamin B.
• Over-closure of the mouth in someone who has been without teeth or dentures for some time.

In young children, the cracks and splits often begin with lip-licking, biting the corners of the mouth, or thumb-sucking.

Treatment depends on the cause and can include lip lubrication, antifungal and antibiotic medication, vitamins, and dentures for a person without teeth.