Rosacea-prone skin: ingredients to avoid.

Rosacea is a very common chronic dermatological disease. In France, it affects 4 million people, predominantly women.

This condition affects the small vessels of the face. It can present in 4 different forms : vascular (rosacea), ocular, papulopustular or hypertrophic. The presence of redness on the face, due to an exaggerated reaction of the blood vessels, is the common point among the 4 forms, but other symptoms can appear such as rosacea acne for example.

Please note : rosacea and redness are often confused due to the common presence of redness on the face. However, these conditions are completely different.

Various factors contribute to the onset of rosacea: the genetics, the dysregulation of the immune system related to the skin, the excessive presence of skin mites (Demodex folliculorum and Demodex brevis) and of certain bacteria, an anomaly in the functioning of the blood vessels or even the dysfunction of the Meibomian glands which are located at the edge of the eyelids in the case of ocular rosacea.

As previously mentioned, the couperose is the most common form of rosacea.

Rosacea is characterised by temporary redness (erythema) or permanent redness (erythrosis) associated with the development on the skin surface of small blood vessels that are thin, red or purple, and individualised, becoming visible to the naked eye (telangiectasias). These rednesses are located in the centre of the face (forehead-eyes-nose-cheeks-chin).

This condition is also accompanied by repeated sensations of heat (hot flushes), and the skin may have a dry appearance with flaking. Rosacea results from excessive dilation of the blood vessels in the face. This skin disease frequently affects people with fair complexions with eyes and light hair.

A skin with rosacea is a sensitive skin that tends to be dry. This skin sensitivity is explained by a high number of nerve endings in the deep part of the skin and by the presence of a substance called "substance P" present locally and in the blood, which causes local inflammation. Therefore, particular attention should be paid to the choice of cosmetic products.

These should have the simplest and most minimalist formulation possible. Choose skincare products without alcohol and without fragrance, as they are very irritating to the skin.

Furthermore, certain active ingredients must be avoided such as:

• Retinol :

Derived from Vitamin A, retinol is a highly effective ingredient in combating oxidative stress and accelerated skin ageing. However, the most common side effect following the use of a retinol-based skincare product is anirritated skin characterised by the onset of redness, itching, and even slight burning. This is why this active ingredient isnot recommended for sensitive skin.

All cosmetics or topicals (prescription-based) containing retinoids are not recommended for skin exhibiting rosacea.

• Alpha-hydroxy acids (A.H.A.):

A.H.A.s are potent keratolytic agents that offer numerous benefits for the skin. This family encompasses various molecules such as theglycolic acid, mandelic acid or even tartaric acid.

Despite their numerous benefits, A.H.A.s can be irritating much like retinol. Therefore, they should be avoided in case of rosacea.

Please note : for exfoliating your skin, it is recommended to use poly-hydroxy acids (P.H.A.). Unlike A.H.A., P.H.A. are gentle exfoliants. With a larger molecular size than A.H.A., P.H.A. penetrate less deeply into the epidermis and are more suitable for atopic, sensitive and/or skin with conditions. Moreover, P.H.A. are alsomoisturising: they capture and retain water in the epidermis andreduceskin dryness by half.

In terms of makeup, it is advisable to opt for light textures and non-comedogenic formulas that do not clog the skin's pores.

• NAVARINI A.A. & al, Swiss S1 guideline for the treatment of rosacea (2017)