What causes chapped lips?
Updated: Mar 15, 2022
I was speaking to one of my friends who had been plagued with chapped lips all winter long. She was miserable, because the chapped lips had gotten so bad that at times it was interfering with her ability to eat and drink, and even enjoy her favorite restaurant. “It doesn’t matter how much water I drink. My lips are still so chapped!“
Chapped lips are a really common condition, but I find that there are frequent misconceptions about what causes chapped lips and how to deal with them.
I’m a dermatologist, and in this post, I want to go over the basics of what to do if you are dealing with chapped lips.
What causes chapped lips?
My friend held a common misconception about chapped lips. She thought that if she could just drink enough water, that she would be able to hydrate her lips. Unfortunately, the causes of chapped lips are more complex than that.
In general, I find that there are three main causes of chapped lips.
Dry skin/dry lips
Irritant contact dermatitis (irritation)
Allergic contact dermatitis (allergy)
Why do some people develop dry skin? Why do some people develop dry lips?
Your skin barrier is amazing. It locks moisture into your skin in order to provide a barrier against the outside world and protects you from all sorts of threats, from extremes of temperature to microbes and chemicals.
For some people, though, that skin barrier just doesn't hold onto moisture well.
For some people, dry skin can be traced back to genetics: their skin simply doesn’t hold onto moisture as well. (That’s me.)
For other people, hormones can play a difference. Individuals with low thyroid levels, for example, are more likely to experience dry skin.
Age can also play a difference, because we don’t produce as many natural moisturizing oils in our skin as we get older.
The environment plays a role also. When the air is very dry, such as when we turn the heat on in our house in the winter, that can start to pull moisture away from our skin. That can then leave you prone to dry skin.
Certain medications can dry out the skin. One example is Accutane. This medication is used for acne and it frequently causes very dry skin and very dry lips.
Why do dry chapped lips sometimes turn into extremely chapped lips?
Dry chapped lips usually respond pretty well to using moisturizers. Many people turn to lip balms, although I personally prefer lip ointments as a treatment for dry lips. When that doesn’t work to treat chapped lips, the most common reason that I see is either irritation or allergy.
What causes irritation of the lips? Why lip licking causes lip irritation and irritant contact dermatitis
When our lips become dry, many people respond by licking their lips. This feels good in the short term – it adds some moisture - but it's actually damaging to the skin of the lips.
When saliva on the lips evaporates, it can take moisture with it.
That sets up what we call a wetting/drying cycle.
The more you wet your lips and then let that moisture evaporate, the more your lips become dry over the long term.
And if this is repeated over and over again, it can lead to extreme chapped lips.
That's known as irritant contact cheilitis (inflammation of the lips due to irritation).
This is actually very common in children. Some children bite their nails, and some children lick their lips. And many times it becomes such an ingrained habit that they don't even notice. (And just like nail-biting, lip-licking can be a very difficult habit to conquer).
And just to make things more challenging, the lip balms used to treat chapped lips can sometimes make the problem worse because they can trigger allergic reactions. Lip irritation can also set a person up for an allergic reaction of the lips.
Some of my patients, to try to heal their dry lips, have turned to lip balms. When one doesn't work, they turn to another. Some have tried multiple different lip products in an effort to get the problem under control.
Unfortunately, those lip balms may actually be worsening the problem.
That's because the ingredients in different lip care products can trigger an allergic reaction. This type of allergic reaction is known as allergic contact dermatitis, and it can be tricky to figure out. The reaction doesn't start right away. In fact, it takes about 2-3 days on average for the reaction to show up. And once it does show up, it can take about 8 weeks for it to finally subside.
That's why it can be so hard to recognize that the lip balms (or lipsticks, or toothpaste, or other lip products) are actually causing a problem.
What you need to know about allergic contact dermatitis to lip balms and chapsticks
These allergic reactions are also known as allergic contact cheilitis, and let me re-emphasize that this is a delayed allergy.
Allergic contact dermatitis is not like your typical food allergy. In that type of allergy, you eat shrimp and then minutes to hours later your lips swell.
In this type of allergic reaction, your lips may become inflamed anywhere from 6 hours to 1 week later.
For some people, this inflammation takes the form of redness, swelling, and even blisters.
For others, it takes the form of redness and flaking, which looks like extreme chapped lips.
If the inflammation is severe enough, it may even require treatment with prescription medications.
What are some of the common causes of allergic contact dermatitis of the lips?
One of my friends asked me about her severely chapped lips at a party. The first question I asked was "Did you start using Burt's bees? or Eos? Or another lip balm lately?" She had. I'm seeing a number of allergic reactions to the flavoring additives that are commonly used in many types of lip balms. For these patients, I usually recommend pure Vaseline petroleum jelly, or even pure coconut oil. But I always caution my patients to be careful, because the Vaseline petroleum jelly sold in the checkout aisle, for example, often has added flavorings.
Sometimes even other flavorings can trigger reactions, such as the ones used in mints, mouthwash, chewing gum, or toothpaste.
The flavorings in lip care products that can trigger allergic reactions are also related to certain foods. That's why, for my patients who don't improve after changing their lip and skincare products, I often recommend avoiding certain foods. These foods are related to a substance called Balsam of Peru, and they include foods such as tomatoes, citrus, and cinnamon.
If you suspect you may be dealing with allergic contact dermatitis of the lips, please see these handouts:
This post goes into more detail about the causes of lip allergic contact dermatitis. It also provides more information on the products that you CAN use that are less likely to trigger allergic reactions.
For a longer list of hypoallergenic skincare products and makeup, please see this list.
How to treat chapped lips
In summary, these are the steps that I recommend if you're dealing with chapped lips:
Start using lip ointment to seal moisture into your skin. In general, I prefer lip ointments over lip balms for patients who are dealing with severe chapped lips.
Ask your friends or family if they've ever noticed that you're licking your lips. Sometimes (often) this is an unconscious behavior, and you may not even realize that you're doing it. If you or your child is unconsciously licking lips, then habit reversal strategies may be helpful.
If your treatments aren't helping, then you may need to consider that this is an allergic reaction. I recommend switching to these products and seeing if you experience improvement. Just remember that it can take 8 weeks (sometimes longer) for the skin on the lips to calm down.
For severe cases, we may prescribe an anti-inflammatory ointment to help with the redness and flaking on the lips
It's also important to see your dermatologist for severe cases, because there are other potential causes of extreme chapped lips
The bottom line is that if you are dealing with chapped lips, there are steps that you can take to help ease your symptoms--and finally get back to enjoying that restaurant.