Cracks or sores in the corner of the mouth can be rather annoying,
like a paper cut — small, and irritating. Fancy medical terms for this
condition include "angular stomatitis," "angular cheilitis," or
"perleche."
A number of different things can be behind the development of such cracks:
- yeast infections
 
- vitamin deficiencies (vitamin B2 or riboflavin)
 
- iron-deficiency anemia (low red blood cells due to too little iron)
 
- allergic reaction to some substance (particularly products
 
 used on the lips, such as lip gloss/stick/balm, and even dental
 
 care/oral hygiene products, such as toothpaste)
 
- poorly fitting dentures (or no teeth or no dentures at all)
 
Sometimes applying an anti-yeast cream [such as ketoconazole (brand
name is Nizoral) that can be found over-the-counter (OTC) at your local
drugstore] to the area will work. You can also mix it with a little dab
of 1 percent hydrocortisone cream, also available OTC. Rub this mixture
over the area 2 - 3 times each day. If you don't see improvement in
under a week, or if the area becomes redder, more swollen, or terribly
uncomfortable, you'll need to make an appointment with your health care
provider or dermatologist. If you continue to have problems with
cracking at the corners of your mouth, check with your health care
provider to see if there are other measures you need to be taking, such
as using vitamin or iron supplements, applying only petroleum jelly on
the lips, switching to a milder baking soda based toothpaste, or being
properly fitted with dentures.