The skin’s barrier protection is not fully developed in the first years of life, and UV-induced skin changes begin early.
Recommendations for photoprotection are part of clinical practice. This is particularly important for infants and young children, and special issues pertaining to this age group are the subject of a recent review.
Infants (<1 year of age) and toddlers (1–3 years of age) have less endogenous protection against ultraviolet (UV) radiation than adults; their skin contains less melanin (the pigment that makes up our skin colour) ; and the stratum corneum (the uppermost part of our skin) of the epidermis is thinner.
Studies in infants who have been carefully protected from recreational sun exposure but not from incidental UV exposure (e.g., inside a car, in the shade, or on a cloudy day) demonstrate seasonal differences in the pigmentation of the outer, but not the inner, aspect of the arms, indicating that even incidental sun exposure can affect the skin.
The importance of early sun protection can also be construed from genetic changes in naevi (moles). Sun exposure early in life is associated with increased numbers of pigmented naevi (moles) , which contain genetic mutations different from those found in congenital naevi.
Although meticulous sun-protective practices have been endorsed by the American Academy of Pediatrics (AAP) and the American Academy of Dermatology, implementation by parents is less than ideal. Between 29% and 83% of children develop sunburn each summer. Because of their higher surface-area-to-body-mass ratio, greater susceptibility to percutaneous absorption, and differences in metabolism of sunscreen products, sun avoidance is the preferred method of photoprotection in this age group. However, the AAP has suggested that small amounts of sunscreen with an SPF of 15 or higher can be applied to small areas of skin (e.g., face, back of hands) of children younger than 1 year, when adequate clothing and shade are unavailable. Care must be taken to use sunscreens that are nonirritating to the skin and eyes. Inorganic filters such as zinc oxide and titanium dioxide do not penetrate beyond the first two layers of the stratum corneum, and tend to be less irritating, and therefore may be the preferred form of sunscreen for infants.
Journal Watch Dermatology July 2011