Skin prone to rosacea: how to combat the harshness of the cold?

Intense skin dryness, discomfort, redness... rosacea is characterized by damage to the skin barrier leading to an increase in transepidermal water loss. However, during the winter season with the cold and dry air, the skin is even more dehydrated, and the blood vessels tend to contract in response to the cold, further enhancing the appearance of redness. The skin becomes more inflamed due to the proliferation of certain inflammation markers and thickens at the level of the horny layer, thus reducing its flexibility.

However, in response to the effects of cold weather, proper hydration can promote the maintenance of the skin barrier's integrity by creating a protective film on the skin's surface. This film limits water loss and maintains an adequate level of skin hydration. Therefore, the use of certain occlusive agents (such as silicones, waxes, butters, etc.) and humectants (like hyaluronic acid, glycerin, etc.) should be prioritized. Emollient agents (ceramides, squalane, vegetable oils and butters, etc.) should also be favored, as they provide reinforcement to the skin barrier. These agents retain the skin's moisture while promoting its protection.

Furthermore, the use of active ingredients such as niacinamide can also aid in repairing the skin barrier. It helps to improve the structure of the epidermis by increasing the production of lipids, such as ceramides. Additionally, anti-inflammatory actives, like the azelaic acid, can reduce visible redness, stabilize blood vessels, and have a soothing effect. These active ingredients help restore the function of the skin barrier, thus leading to a decrease in irritation and redness.

Exposure to cold activates a pathway of channels known as TPR, particularly the TRPA1 channel. This channel plays a crucial role in detecting temperatures and signaling them to the peripheral nervous system. However, a drop in temperature will trigger the activation of nociceptive neurons called ANKTM1. In response to the cold, the vascular system causes vasodilation, resulting in more intense redness.

In order to protect the skin from exposure to cold, it is necessary to cover up. Since the majority of rosacea symptoms affect the face, it is important to cover up by wearing a hat and a scarf that covers the affected areas (chin and cheeks), or, in cases of extreme cold, to opt for wearing a balaclava.

In the face of the cold outdoor climate, hot showers and baths can be comforting in winter. In the same way that the neuro-receptors present on the skin's surface detect drops in temperature, high temperatures can also cause a disruption of the skin barrier.

Just like cold, excessive heat is equally a triggering factor for rosacea. Responsible for activating the TRPV1 and TRPV2 pathway, excess heat selectively stimulates sensory neurons that signal variations to the nervous system.

These neurons are responsible for the sensation of pain felt in case of a burn. The body stores the heat, thereby triggering the dilation of blood vessels on the skin's surface to dissipate it. The heat also increases water loss, thus promoting dehydration.

In the case of rosacea, it is particularly recommended to avoid hot showers and baths in order to limit the development of these symptoms. Steam rooms and saunas should also be avoided due to the hot vapors they produce.

Similar to hot showers and baths, heating can be a source of excessive heat. Indeed, through the activation of TRPV1 and TRPV2 pathways, blood flow increases, exacerbating the appearance of rosacea symptoms. Therefore, despite the sensation of cold, it is preferable for individuals suffering from rosacea to limit indoor heating. The ideal is to maintain a surrounding temperature of around 62.6 to 64.4°F.

Both outdoors and indoors, the dry winter air can promote skin dehydration, leading to irritations and feelings of tightness. The use of a humidifier can help to offset this loss of moisture in the air and thus help to maintain a 30 to 50% indoor humidity level. The use of this tool can then limit water loss and skin dryness.

Coffees, hot chocolates, soups, mulled wines... winter is a season conducive to the consumption of hot beverages for their comforting aspect. However, the consumption of these types of drinks causes an excessive heat intake to the body, creating a sensation of overheating.

This phenomenon employs the same mechanisms as those previously discussed. The body will attempt to dissipate heat on the surface, blood vessels will dilate and induce significant erythema. Therefore, very hot drinks should be limited for those affected by rosacea, it is preferable to consume beverages at room temperature.

The consumption of alcohol can lead to an increase in the production of pro-inflammatory cytokines, thereby increasing the risk of inflammation and associated symptoms. Alcohol also promotes the release of catecholamines, causing vasodilation in the face. Alcohol consumption is ideally limited in cases of rosacea. It is preferable to limit consumption to one glass per week.

Spicy foods such as pepper, mustard, or chili peppers contain a molecule, capsaicin, which is responsible for the sensation of spiciness and the heat flushes associated with their consumption. Indeed, this molecule will stimulate the activity of the TRPV1 receptor and trigger the release of the neuropeptides PACAP and CGRP through nociceptive mechanisms.

These neuropeptides in turn induce the dilation of blood vessels, which is the cause of the redness found in rosacea. Besides the consumption of chili peppers, spicy foods like garlic can also be the source of this type of effects. The molecule responsible for this phenomenon in garlic is allicin. It operates following the same mechanisms as capsaicin.

Given that it contributes to the increase of inflammation and exacerbates skin redness and irritation, the consumption of spicy foods should be minimized as much as possible, especially during this period when the skin is even more sensitive.

Some cosmetic products can cause bothersome reactions, such as itching, irritation, skin dryness, flaking, or even burning sensations. They can further sensitize the skin and induce disruptions in the skin barrier, making the skin more vulnerable to external aggressions like cold weather.

Indeed, several natural aromatic compounds such as camphor, menthol, thymol, and sodium lauryl sulfate are known to activate the TRPA1 pathway. They could therefore trigger rosacea flare-ups and cause additional discomfort in affected individuals.

To avoid these types of adverse reactions, it is recommended not to use cosmetics containing these aromatic components, especially essential oils which should be avoided. Furthermore, the use of products containing alcohol or synthetic fragrances should also be avoided, as they have a drying effect and can cause irritations.