Photoprotective products in newborns and infants: characteristics, safety, and selection criteria

In newborns and children during the first year of life, topical photoprotection represents a measure complementary to physical and behavioral protection strategies and must never replace avoidance of direct sun exposure, staying in the shade, and the use of photoprotective clothing. The choice of the most appropriate product requires knowledge of the characteristics of different filter systems and the physiological peculiarities of the skin in this age group, in order to maximize photoprotective efficacy and minimize the risk of undesirable effects.

Major scientific societies recommend avoiding the routine use of sunscreens in infants under six months of age. If accidental exposure cannot be avoided and physical measures are insufficient, it is possible to apply a limited amount of product exclusively to sun-exposed areas that cannot be protected by clothing or a hat. After six months of age, when sun exposure is unavoidable, the use of broad-spectrum photoprotective products represents an important additional preventive measure.

Mineral filters and organic filters

Photoprotective agents are traditionally divided into mineral (inorganic) filters and organic (chemical) filters, although this classification mainly reflects their chemical composition rather than the real mechanism of action. Modern evidence shows that both groups of filters exercise their protective activity through a combination of reflection, scattering and especially absorption of ultraviolet radiation.

• The mineral filters, mainly represented by zinc oxide (zinc oxide) and titanium dioxide (titanium dioxide), guarantee broad-spectrum protection against both UVB and UVA and are characterized by high photostability, minimal chemical reactivity, and low sensitizing potential. Thanks to their favorable safety profile, they are generally considered the first choice in products for infants, children with sensitive skin, and individuals suffering from atopic dermatitis or other dermatoses characterized by altered barrier function.
• The organic filters include numerous molecules with different absorption spectra, frequently combined to achieve effective protection against the entire UV spectrum. Newer generation formulations use filters characterized by high photostability and a better toxicological profile compared to compounds used in the past. However, some ingredients, such as octocrylene, oxybenzone (benzophenone-3) and octinoxate (ethylhexyl methoxycinnamate), have occasionally been associated with allergic contact dermatitis, photoallergic dermatitis, and irritative phenomena, although these events are overall infrequent.

In the first year of life, characterized by an epidermal barrier still in the maturation phase, high skin permeability, and a higher body surface area to weight ratio, it is appropriate to prioritize formulations with low irritative potential, fragrance-free and containing the smallest possible number of sensitizing substances.

Systemic absorption and safety of UV filters

In recent years, particular attention has been paid to the possible systemic absorption of some organic filters. Pharmacokinetic studies conducted under experimental conditions of extremely intensive application have documented plasma concentrations of some molecules. However, these protocols involved usage patterns significantly higher than actual use and usage conditions in the pediatric population.

To date, there is no clinical evidence demonstrating endocrine effects, reproductive or systemic effects related to the use of approved sunscreens under normal conditions of use. The main international regulatory agencies therefore continue to consider the benefit-risk ratio of authorized photoprotective products favorable, highlighting how the benefits deriving from the prevention of actinic damage and photocarcinogenesis are clearly superior to potential theoretical risks.

Characteristics of products intended for infants

In children in the first year of life, formulations specifically developed for pediatric skin should be preferred, characterized by:

• broad-spectrum protection (UVA and UVB)
• SPF ≥50 or SPF 50+
• high UVA protection (UVA-PF compliant with European recommendations)
• high photostability
• water resistance when appropriate
• absence of fragrances, essential oils, and preservatives with high sensitizing potential
• dermatologically and pediatrically tested formulations
• preference, where possible, for predominantly mineral filter systems after six months of life and in children with sensitive skin

Methods of application 

The effectiveness of any photoprotective product depends not only on the declared protection factor, but also on the amount applied. The studies used to determine the Sun Protection Factor (SPF) involve the application of 2 mg/cm² of product, an amount rarely reached in clinical practice.

In infants, sunscreen should be applied evenly to all sun-exposed areas approximately 15–30 minutes before exposure, avoiding contact with eyes, mucous membranes, and hands, which are frequently brought to the mouth. Application must be repeated every 2 hours and after bathing, intense sweating, or towel drying, even in the case of products labeled “water resistant”.

It is essential to remember that no sunscreen guarantees complete protection nor should it be used to intentionally prolong time spent in the sun. In the first year of life, the photoprotector therefore represents the third level of defense, after direct exposure avoidance, shade seeking, the use of clothing with a high ultraviolet protection factor (UPF), wide-brimmed hats, and prams or strollers equipped with hoods made of UPF 50+ certified fabrics, designed to simultaneously ensure effective shielding from ultraviolet radiation and adequate ventilation and air circulation, avoiding the risk of overheating the infant.

Conclusion

In newborns and infants, topical photoprotection should only be considered as a support to physical and behavioral measures. In the first six months, the use of sunscreens should remain limited to exceptional situations, on small areas that cannot otherwise be protected. After six months, when sun exposure cannot be avoided, it is preferable to choose broad-spectrum pediatric products, SPF 50+, fragrance-free and free of sensitizing substances, prioritizing where possible formulations that are predominantly mineral, especially in the case of sensitive skin. Even in these cases, however, the main protection remains shade, together with suitable clothing, hats, and well-ventilated shielding devices.