Why cracks keep forming at the corners of the mouth, according to dermatologist Dr Andrea Suarez

Cracking, soreness, and redness at the corners of the mouth can make eating and speaking uncomfortable. While many people assume it is just dry skin, Dr Andrea Suarez, a board-certified dermatologist based in the United States, said it is often angular cheilitis.

She said angular cheilitis occurs when the skin barrier at the corners of the mouth breaks down, leaving the area vulnerable to infection. Once the skin is damaged, yeast - most commonly candida - can colonize the area, slowing healing and causing pain.

“It’s usually a combination of skin barrier breakdown followed by yeast overgrowth,” she said.


What causes angular cheilitis

Dr Suarez said moisture is the most common trigger. She explained that saliva tends to collect at the corners of the mouth, which gradually weakens the skin.

She said this saliva exposure often occurs during sleep, when a person drools, but it can also happen during the day in people who frequently chew gum or wear dentures that do not fit properly. In some cases, she added, the natural shape of the mouth plays a role, especially when the corners turn downward, allowing saliva to pool.

According to Dr Suarez, this constant wetness acts as the starting point for many cases of angular cheilitis. Once the skin is irritated, it becomes easier for yeast to grow, which leads to cracking and inflammation.

She also said that while the condition is common, it should not be ignored, especially if it keeps returning.

What is recommended for treatment and prevention

Dr Suarez said angular cheilitis can often be treated with over-the-counter antifungal creams, such as clotrimazole, which target the yeast component of the condition.

However, she said treatment works best when combined with steps to protect the skin. She explained that applying a simple barrier, such as plain petroleum jelly, to the corners of the mouth can help shield the skin from saliva and reduce irritation.

She said preventing moisture from sitting on the skin is key to stopping the condition from recurring.

Dr Suarez added that if angular cheilitis keeps coming back, it may be worth looking beyond local irritation. She said repeated episodes can sometimes be linked to nutritional deficiencies, including low iron levels or certain B vitamin deficiencies.

In such cases, she said, treating the skin alone may not be enough, and addressing the underlying deficiency becomes essential.

When to seek further advice

Dr Suarez said that persistent or recurring cracking at the corners of the mouth should prompt a closer look at lifestyle habits, oral appliances, and overall health. With the proper treatment and preventive care, she said, most cases can heal and stay away.

The key, she explained, is understanding that angular cheilitis is not just dryness; it is a signal that the skin barrier needs protection and, in some cases, that the body needs support.