Chapped lips: mistakes to avoid.

The lips (vermilion) are considered a semi-mucous membrane, which means they have a somewhat different structure from the surrounding skin. They are composed of a non-keratinised stratified squamous epithelium, highly vascularised, which essentially corresponds to layers of flattened skin cells, covered with a very thin horny layer (only 3 to 5 layers, compared to up to 16 for the facial skin).

Unlike the rest of the body, the skin of the lips does not possess sweat glands, nor sebaceous glands, which play a key role in skin hydration and protection. Their only natural barrier against dehydration and external aggressions relies on their cellular structure, making them more prone to chapping, dryness, and irritation.

That's why it's essential to take care of them daily, particularly by applying a protective lip balm. This simple act helps to limit moisture loss and maintain the lips' suppleness, especially in winter, when the cold and wind accelerate their drying out.

Licking your lips may seem like a natural reflex when they become dry or chapped. However, although this action may not pose a problem if done occasionally, it only exacerbates the situation by triggering a vicious cycle of drying and irritation if it is repeated throughout the day.

But what happens when we lick our lips? Saliva contains digestive enzymes, such as amylase and maltase, which weaken the delicate skin of the lips, making it more vulnerable to external aggressions. Moreover, the moisture provided by saliva for a brief moment evaporates quickly, taking with it the lips' natural hydration and thereby exacerbating their dryness. Over time, this behaviour can lead to painful chapping and cracking. To avoid these discomforts, it is preferable to regularly apply a moisturising and repairing lip balm, rather than succumbing to this counterproductive reflex.

Excessive lip licking can lead to a factitious exfoliative cheilitis, a chronic condition characterised by the presence of crusty scales on the lips, which can encourage even more frequent licking and perpetuate the problem.

Although hot water can provide temporary relief, its application on the lips is not recommended. It can not only exacerbate dryness, but also cause superficial burns, thereby worsening irritations and delaying healing. By further weakening the thin corneal layer of the lips, it promotes the appearance of chapping, painful cracks and increased dehydration. To preserve the integrity of the lips, it is recommended to use lukewarm water (this also applies to the time spent in the shower) and to apply a lip balm to maintain their integrity.

Although tempting, it is also advised against scratching or peeling off dead skin.

Matte lipsticks provide a sophisticated and elegant finish due to their velvet-like texture. Their long-lasting wear and intense pigmentation make them a staple in makeup. However, despite advancements in formulations, they tend to be more drying than their satin counterparts.

This sensation of dryness can be explained by their composition: to ensure a matte effect and long-lasting wear, these lipsticks contain fewer moisturising agents (butters, waxes, etc.) and more absorbent powders (silica, talc, etc.) and dry oils (alkanes), used for their ability to evaporate quickly. These ingredients allow the lipstick to fix the pigments onto the lips, without leaving a greasy film.

Indeed, the same principle applies to long-lasting lipsticks, whose formulas are designed to strongly adhere to the lips, often at the expense of comfort.

However, this rapid evaporation also contributes to the drying out of the lips, by limiting their supply of nourishing lipids. Even if you apply a moisturising balm beforehand, the adherence of the lipstick can be reduced and its durability compromised. To avoid this effect, tinted lip balms provide an ideal alternative, offering both hydration, comfort and a subtle touch of colour.

Tip : Tinted lip care products can provide a certain degree of sun protection for the lips, as they contain pigments known as iron oxides (CI 77499, CI 77492, CI 77491, etc.), which share UV-reflecting properties structurally similar to those of zinc oxide. However, this remains an additional benefit, but they are not sufficient to guarantee UV protection if they do not contain sun filters.

Menthol, camphor, capsaicin, peppermint essential oil... These ingredients are often added to lip balms for their cooling effect, particularly on irritated and chapped lips. However, while they provide temporary relief, they can further dehydrate and irritate the lips. In some cases, these compounds can also trigger a contact allergic dermatitis, also known as contact allergic cheilitis.

This delayed hypersensitivity reaction can manifest in two forms. In acute cases, the lips become red, swollen, and covered in small vesicles that may ooze before forming crusts. More commonly, cheilitis takes on a chronic form with dry, scaly, and cracked lips, which can be painful. Unlike immediate allergies, symptoms usually appear a few hours after contact with the allergen and can persist for several days, or even weeks, if the use of the irritating product continues.

In addition to these ingredients, fragrant compounds, allergenic molecules found in essential oils (such as cinnamaldehyde, citral, eugenol, etc.), as well as alcohols can also trigger or exacerbate these reactions by further drying out the delicate skin of the lips. To avoid these discomforts, it is essential to choose products formulated without known allergens and suitable for the sensitive skin of the lips.

Protecting your lips from the sun is just as crucial as safeguarding the rest of your skin. Unlike other body areas, the lips are thinner and contain very little melanin, this pigment that naturally helps the skin defend against UV rays. Depending on the skin tone, this low melanin concentration makes them particularly vulnerable to sun-induced damage. Without protection, they are exposed to an increased risk of photodamage, hyperpigmentation, actinic cheilitis and, in the most severe cases, to squamous cell carcinoma, a type of skin cancer.

The daily application of a lip balm with an SPF of 30 or higher is therefore essential to prevent these harmful effects and preserve the health of the lips. This simple action helps to limit the damage caused by UV rays and maintain healthy lips throughout the year.

In addition to sunscreens, it is also necessary to look for lip products containing antioxidants (such as Vitamin E, etc.) to prevent cellular damage, humectants (hyaluronic acid, glycerine, etc.) to hydrate the lips, and emollients (vegetable oils, vegetable butters, etc.) for a softening effect.

Just like other skincare products, lip care items (peelings, masks, balms, glosses or lipsticks) have a limited shelf life. It is often mistakenly thought that using an expired product is without consequence. However, over time, visible signs can alert us: its texture may change, its colour may alter due to a degradation of pigments or an oxidation of the product after repeated exposure to air or sunlight, the emergence of a rancid or unusual smell, or even a separation of components which is a sign of a deterioration in its formulation.

Depending on the formulation of the product, lip care products have a Period After Opening (PAO) between 6 months and 24 months.

Even if the product appears to still be usable, its effectiveness is compromised and its application can become problematic. In addition to no longer delivering the anticipated benefits, this action can irritate the lips and cause itching, redness or burning sensations. The hydrating oils and butters it may contain eventually degrade, depriving the lips of their protection and exposing them more to environmental factors. Furthermore, bacteria and fungi can proliferate over time, increasing the risk of infections, particularly if the lips are chapped or cracked. To maintain lip health, it is therefore essential to respect the lifespan of products and renew them regularly.

• ADEMOLA J. & al. Lip sun protection factor of a lipstick sunscreen. Dermatology (2001).

• BENCHIKHI H. & al. Les chéilites allergiques : étude de 17 cas. Revue Française d'Allergologie (2009).

• DEKOVEN J. & al. Acute allergic contact dermatitis of the lips from peppermint oil in a lip balm. Dermatitis (2010).

• ELHAOURI M. & al. Chéilite exfoliative factice. Médecine thérapeutique (2018).

• ZITO P. M. & al. Anatomy, head and neck, lips. StatPearls (2023).