Sun damage to the skin: the risks of sunburn and what to do

“Sunburn, meaning skin damage caused by excessive exposure to ultraviolet (UV) rays — invisible radiation emitted by the sun — can be classified according to severity, similarly to burns,” explains the physician.

Depending on the degree, different symptoms may occur. Specifically:

• First-degree sunburn: characterized by redness and burning affecting the most superficial layer of the skin. It usually heals spontaneously;
• Second-degree sunburn: affects deeper skin layers and causes redness, blistering, swelling, and intense pain;
• Third-degree sunburn (rare): causes deep tissue damage. In addition to second-degree symptoms, it is often associated with fever and joint pain, and scarring is common. Due to the risk of infection and tissue necrosis, hospital care may be required.

Tanning as a defense mechanism

One aspect that is often misunderstood concerns tanning itself. The production of melanin, which gives the skin its characteristic golden-brown color and is often considered aesthetically desirable, is actually a defensive response to damage.

The skin activates a protective mechanism to shield cellular DNA from ultraviolet radiation in an attempt to limit deeper injury.

As ultraviolet rays penetrate the skin, they may cause cellular damage. Specifically:

• UVA rays contribute to premature skin aging (wrinkles and loss of elasticity) and oxidative damage, penetrating deeper into the skin, often without visible symptoms;
• UVB rays are primarily responsible for sunburn and mainly affect the superficial layers of the skin;
• UVC rays are the most energetic and potentially the most harmful, but they are almost completely absorbed by the ozone layer and do not reach the Earth’s surface. They are mainly found in artificial sources (such as germicidal lamps) and, in cases of unprotected exposure, may cause acute skin and eye damage as well as cellular injury. References to “UVC protection” in some sunscreens generally relate to laboratory testing or a theoretically “fully extended” UV spectrum coverage, without practical relevance for everyday sun exposure, although it may potentially be useful for workers exposed to artificial UV sources.

All 3 types of UV radiation are capable of damaging cellular DNA in different ways and may contribute to the development of skin cancer. In everyday life, however, exposure involves almost exclusively UVA and UVB rays, which reach the Earth’s surface.

The visible effects of sunburn may last from 1 to several days, depending on severity, but the biological damage may persist much longer. Even when the skin appears normal again, the underlying cells initiate a complex self-repair process that may last for weeks and is not always fully effective. Some damage, if extensive enough, becomes permanent.

The skin’s memory: sun damage that does not appear immediately

The skin has a true “biological memory”: every excessive exposure to sunlight leaves a mark on cellular DNA. Over time, this damage accumulates and may lead to:

• premature aging;
• skin discoloration and spots;
• cellular alterations causing cells to function improperly and lose repair capacity;
• increased risk of skin cancer.

This process is silent and progressive, which is why the consequences often become visible only years later.

Unprotected sun exposure during childhood: a future risk

“Unprotected sun exposure and sunburn during childhood and adolescence are particularly dangerous,” explains Dr. Guanziroli. “At this age, melanin provides less protection and the skin is more vulnerable to DNA damage, with effects that may become significant and appear many years later.”

Even a few episodes of sunburn and excessive exposure to UV rays (UVA and UVB) early in life may increase the risk of developing skin cancer and other skin disorders in adulthood. This does not mean such conditions will certainly occur, but that the likelihood is increased.

The main tool for monitoring skin health and detecting invisible sun-related damage at an early stage is regular dermatologic examination, especially before summer.

A dermatologic consultation with mole mapping allows specialists to identify and monitor any changes in the skin over time.

In particular, videodermoscopy is a non-invasive technique that uses a high-magnification camera to obtain detailed images of moles, making it possible to observe skin structures invisible to the naked eye and to archive and compare images over time in order to detect even minimal changes during follow-up visits.

Prevention remains the most effective weapon for protecting the skin from the sun. This can be achieved by:

• using a broad-spectrum sunscreen (UVA and UVB) with an SPF appropriate for your skin phototype throughout the year (not only in summer and not only when it is sunny), reapplying it at least every 2 hours during direct sun exposure or after swimming;
• avoiding direct sun exposure during the hottest hours of the day (approximately between 11:00 AM and 3:00 PM), when UV rays are strongest;
• wearing hats, UV-protective clothing (UPF 50+), and sunglasses with UV filters. The eyes can also be damaged by UV rays, which may contribute to conditions such as early cataract formation.

“It is important to remember that, although sunscreen is the most important tool we have to defend the skin against UV rays, it does not block them 100%. It therefore needs to be part of an overall protection strategy and a lifestyle based on correct habits and awareness of risks,” concludes the physician. “The skin should be protected every day, not only during holidays.”