What causes the sides of your mouth to crack

As the temperatures drop and indoor heating cranks up, it’s easy to find yourself revisiting the annual, cold weather habit of licking your lips. Even though we know it only makes things worse. Whether it’s caused by cold weather, sunburn, or some other element, dry, cracked corners of the mouth are supremely uncomfortable. We talked to board-certified dermatologists about what causes this to happen, how to prevent it, and what to do when it’s already there.

Meet the Expert

• Amanda Doyle is a New York City-based dermatologist. She serves as faculty at Mount Sinai Hospital.
• Kenneth Howe is a New York City-based dermatologist who focuses on both aesthetic and medical dermatology. 
• Marie Hayag is a board-certified dermatologist with Fifth Avenue Aesthetics in New York City.
• Orit Markowitz is a New York City-based board-certified dermatologist who specializes in non-invasive skin cancer treatment.

What Causes Cracks at the Corner of the Lips?

Dry, cracked corners of the mouth can occur for various reasons, ranging from environmental factors to daily habits. For example, everything on this (fairly long) list can be a contributing factor.

• Cold weather 
• Wind exposure
• Sunburn
• Vitamin deficiencies (e.g., B1, B2, and B3)
• Mouth breathing
• Drooling while sleeping 
• Infection
• Certain lip shapes (lips that turn downward on the corners)
• People who have dentures
• Certain candies and gum
• Tartar control toothpaste

Dermatologists refer to this condition as Angular Cheilitis. Essentially, it’s a condition that irritates the corners of the mouth. Our lips create an angle characterized by bleeding, blistering, cracking, itchiness, redness, pain, scaliness, swelling, and burning. 

When we lick our lips, drool, or basically do anything that exposes our mouths to saliva can be a culprit. This is because the enzymes in saliva can cause the skin to degrade, which, in turn, leaves it vulnerable to infection and inflammation. Essentially, New York City-based, board-certified dermatologist Amanda Doyle explains, “saliva build-up creates cracks and dryness and also allows for certain types of bacteria and yeast to grow.”

Essentially, everything about our mouths lends itself to this sort of problem. As New York City-based, board-certified dermatologist Kenneth Howe calls it “a perfect storm,” and there are four key reasons this is the case. First of all, “this is thin skin,” Howe says, “it’s facial skin, which is thinner, and it’s on/near our lips, which is even thinner.”

Secondly, it’s mobile skin; in fact, it’s “probably the most mobile on the body.” The angles of our mouths are subject to constant movement, whether from talking, eating, yawning. “And it’s not just the simple movement of opening and closing—the site is also stretched,” Howe explains. Third, “this is wet skin. There’s a lot of saliva here! That moisture can have the effect of rinsing away the protective lipid barrier on the skin surface. The result: less pliancy. More cracking!” Finally, this is a skin fold, and as a result, “a pocket can form at the site, which can retain moisture,” Howe says, noting that when that happens, the skin can become irritated or infected with yeast.

Prevention

To prevent this condition, explains New York City-based, board-certified dermatologist Marie Hayag, “It’s important to make sure you’re drinking lots of water and staying well-hydrated.” Making a true habit of using a thick, occlusive lip treatment is also key. Though using a lip balm is simple, Howe notes that many have trouble making it a true habit—and for it to work, it does have to be. “You need to have a lip balm with you at all times—refresh and replenish!” he says. And the fact of the matter is that the choice of lip balm matters too. “Many common lip treatments are loaded with preservatives that are not good for the skin,” notes New York City-based, board-certified dermatologist Orit Markowitz. She recommends looking for a thick product with fewer ingredients and advises applying before exposure to harsh weather, under sunscreen, and increasing application when you get sick. 

There are also certain behavioral adjustments we can make. Doyle recommends “removing any residual saliva that builds upon the area so that it doesn’t pool around the mouth” (dabbing away excess saliva) and putting an occlusive balm (like Vaseline or Aquaphor) at the corners to prevent overdrying.

In some cases, Doyle explains, if there are any “anatomical issues that could contribute to folds around the mouth or downturned lips,” filler can be used to lift the sides of the lips and restore volume, which in turn can help prevent pooling of saliva. 

Finally (although, yes, it’s easier said than done): stop licking your lips once and for all. Doing this when our lips are already dry and cracked is a natural response—it makes them (temporarily) look and feel better. “But it makes things worse—much worse—in the end,” Howe says. “The saliva evaporates and in turn “wicks” moisture off the lips. So we’re drier than we were, to begin with!” he explains. 

Treatment

If even abundant slathering of lip balm doesn’t work—it’s time to see a board-certified dermatologist. In addition to treatments like Vaseline Original Petroleum Jelly ($5) and CeraVe Healing Ointment, a dermatologist may prescribe a topical steroid or antifungal treatment to pair with an occlusive balm. Often these treatments are used twice daily for two-to-four weeks. “If it’s not resolving with this, or there are other signs and symptoms of vitamin deficiencies, this needs to be evaluated so they can be addressed as well,” Doyle says.  

Key Ingredients

Petroleum jelly is composed of natural mineral oils and waxes. It helps seal in moisture, soothe cuts, and accelerate the skin healing process.

Avoid over-the-counter antibiotics like bacitracin or polyisoprene, Markowitz says, adding that “more often than not, these can cause an allergic reaction themselves, often worsening the issue.” TLDR: before temps get any colder, stock up on one of those giant tubs of Aquaphor and use it frequently and generously!

Why is my mouth cracking on the sides?

What deficiency causes cracks at corner of mouth?