48% of 18-25 year olds have noticed a worsening or appearance of a skin disease, during the Covid crisis, in particular because of the stress linked to this period, according to a study by the French dermatology society in 2021. Some people note the impact of pollution or global warming on the appearance of their skin. All of these aggravating factors can be summed up in one word: the exposome. But what is it exactly? Answer with dermatologists.
What is the exposome?
“Invented in 2005 by British epidemiologist Christopher Wild, this concept refers to theall environmental factorseither internal or lifestyle-related, to which the organism is exposed from conception to the end of its life“, explains Dr. Stéphanie Leclerc-Mercier, dermatologist. The main ones that have shown effects on the health of the skin are “ultraviolet rays from the sun, stress, pollution, tobacco, poor diet, hormonal variations and lack of sleep“, specifies Pr Thierry Passeron, dermatologist.
What is the exposome’s share of responsibility in skin diseases?
According to a study by the International Agency for Research on Cancer (IARC), the sun’s UV rays are responsible for nearly 65% of melanomas (the most serious skin cancer) and 90% of other skin cancers. For inflammatory skin diseases (acne, psoriasis, eczema, etc.), “there is still little data here. That said, it is clear that the exposome plays a major role; which warrants attention“, notes Dr. Anne-Céline Davaine, dermatologist.
Which exposome factors promote acne?
In a 2020 international survey of 6,679 people aged 15 to 39, Prof. Brigitte Dréno and her colleagues identified five major factors : diet (including dairy products and sweets), pollution, stress, climate and exposure to the sun. A study conducted among 452 Indians, and published in the Journal of Dermatology in 2002, revealed a worsening of acne during the summer in 56% of patients. This because “heat, high humidity and perspiration.”
What about eczema and psoriasis?
Two factors seem particularly deleterious here: pollution and stress, which flare up the inflammation process at the origin of these two pathologies. A large German study, published in 2019 in the journal The Hautarztshowed a “significant positive association “between eczema and automobile pollution and an increased intensity of symptoms in the event of high concentrations of atmospheric pollutants. But, good news, “in general, the sun [à dose raisonnable et pas entre 11 et 16 heures, lorsque les UV sont les plus intenses, ndlr] reduces the extent and severity of the lesions of these two diseases“, emphasizes Professor Passeron.
How to limit the harmful effects of the exposome?
It is enough to apply the hygieno-dietetic measures usually recommended to maintain good general health: “Eat a balanced diet without excess sweets and fatty foods, sleep at least 7 hours a night, walk at least 30 minutes a day to reduce stress, protect yourself from the sun, etc..”, recalls Dr. Davaine.
Certain cosmetic products can also help: this is the case in particular “sun creams, crucial for preventing skin cancer and – a less well-known fact – for limiting flare-ups of certain inflammatory dermatoses; and “syndets” cleansers, without soap, less drying than soap and, therefore, more suitable for dry skin or skin with atopic dermatitis or psoriasis“, illustrates Dr. Stéphanie Leclerc-Mercier, dermatologist. But others are to be avoided: in particular “oily moisturizers, essential oils, and scrubs, all of which can make acne worse“, lists Pre Brigitte Dréno. In any case, wash your face well at night to remove sebum and accumulated pollutants. To find out more, ask your dermatologist for advice.
Can climate change make skin disorders worse?
Alas, yes… Researchers believe it could blast several of these diseases, including psoriasis and atopic eczema. “Higher temperatures risk altering the skin microbiome, the set of bacteria that naturally live on our skin, and increase sebum production and sweating, which promotes breakouts.“, enlightens the Pre Dréno.
Global warming will also contribute to the survival, in France, ofinsects that we did not find until now in our latitudes : mosquitoes of the genus Aedes, etc. However, these are capable of transmitting viruses which can induce unusual skin disorders in our country, such as “measles-like rashes and petechiae [petits points rouges à la surface de la peau, ndlr] in the case of dengue virus; or maculopapular rashes [formant de petites bosses, ndlr] in the case of the Zika virus“, ends Professor Passeron.