Baby in the sun: what are the risks?

The skin of babies differs from that of an adult and is more vulnerable and fragile. During the first six years of life, the skin barrier gradually develops and does not yet offer its full protection. It is indeed estimated that the epidermis of infants is about 20% thinner than that of adults. This allows allergens, pollution particles, bacteria, and also UV rays from the sun to pass through much more easily. These can penetrate more deeply into children's skin and easily reach the dermal papillae and dermal capillaries, leading to photodamage.

Furthermore, the melanogenesis process is only partially developed in children under three years old, making them highly vulnerable to the dangers of the sun. The primary role of melanin is indeed to protect the skin from external aggressions, particularly against UV rays. Through a "capping" phenomenon where melanin wraps around the nuclei of keratinocytes, this pigment provides some protection to the genetic material. However, this defence mechanism remains incomplete: approximately 15% of UVB still manage to reach the basal layer of the epidermis and 50% of UVA reach the dermis.

Babies, being more delicate than adults, must absolutely avoid direct exposure to the sun.

Sunstroke.

When we talk about the sun, we also refer to high temperatures and perspiration. This physiological phenomenon is a way for the body to balance and maintain its temperature at 36°C. However, the sweat glands, which are responsible for sweat production, are not yet fully active in newborns, making them unable to regulate their own temperature. As a result, their temperature can rise rapidly, leading to sunstroke, which is characterised by intense redness of the head and the baby crying due to headaches and dizziness.

Sunburns.

Triggered by the sun's UVB rays, sunburn is the result of ainflammatory processleading to the dilation of blood vessels and a reddening of the skin. This reaction appears 8 to 24 hours after exposure. On a baby's skin, the burn is characterised by red and painful lesions and sometimes blisters. The skin is also very dry. The redness and lesions usually subside after a few days. Once the burn is fully absorbed, the skin tends to peel. In case of sunburn, ensure to properly hydrate and nourish your baby's skin to aid in healing.

Adult-age melanomas.

In babies, sunburn can worsen to the point of causing the formation of a melanoma, a type of skin cancer, once they reach adulthood. The risks increase progressively as the baby has a light phototype. Melanomas result from the mutagenic activity of UV rays, that is, their ability to induce genetic mutations in skin cells. UV rays can also cause DNA damage. If this damage is not properly repaired, cells can divide uncontrollably, leading to the formation of a tumour. Furthermore, it is important to note that studies show that the risk of melanoma increases by 75% when sun exposure begins before the age of 30.

Advice : Some actions can help prevent these risks during family walks, such as wearing covering clothes, a wide-brimmed hat, sunglasses and regularly applying a sunscreen.

• PUGLIESE P. The skin, free radicals, and oxidative stress. Dermatology Nursing (1995).

• BALK S. J. Technical report - Ultraviolet radiation: a hazard to children and adolescents. American Academy of Pediatrics (2011).

• BUSTER K. & al. Photoprotection in specific populations: Children and people of colour. Journal of the American Academy of Dermatology (2016).