Skin damage from sun exposure: signs, prevention and treatment

How does sunlight damage skin?

Ultraviolet radiation, or UV, penetrates the skin and can damage or kill skin cells. UVA contributes to ageing and damage in deeper skin layers. UVB is the main cause of sunburn, but both contribute to skin damage. UV also damages DNA, the instructions inside cells. Skin has repair mechanisms, but accumulated damage can lead to ageing changes and cancer. Burning is not the only sign that sunlight has affected your skin.134

Sunburn can appear a few hours after exposure rather than while you are outside. Delayed tanning becomes noticeable about two days after exposure and is strongest about a week later. A tan develops because skin produces more melanin, its protective pigment. The colour fades as new cells replace the tanned surface cells; that fading is a change in pigment, not a measure of deeper damage.14

What does lasting sun damage look like?

Repeated exposure can produce several changes, especially on the face, neck and arms:

• Fine wrinkles or deeper lines.
• Uneven colour, freckles and age spots.
• Rough, dry or leathery texture.
• Loss of elasticity and loose skin.
• Visible small blood vessels and easy bruising.
• Thin, fragile skin.
• Dry, scaly patches called actinic keratoses, which are precancerous growths.

Natural ageing affects the whole body, including skin usually covered by clothes. Sun damage adds changes to areas exposed regularly. Normal ageing and sun damage can happen together, so the calendar does not deserve all the credit. Ageing skin also becomes thinner, produces less oil and heals more slowly. Comparing regularly exposed areas with protected areas can make sunlight's contribution easier to see.56

Who needs to be especially careful?

People with fair skin who burn easily are more vulnerable to photoageing, the medical name for ageing caused by sunlight. Long periods outdoors, living at high altitude or in tropical regions, and indoor tanning also increase exposure. Darker skin has more pigment protection, but sun protection is recommended for every skin tone. If you have already had skin cancer, protection can reduce the risk of another skin cancer.57

UV exposure is greater around solar noon and in summer, and increases at altitude and near reflective surfaces such as snow or sand. Cloud cover reduces exposure compared with clear conditions, but daily protection still matters on overcast days. Cold weather is not a reason to stop protecting exposed skin.24

How to prevent further damage

1. 1Plan for shade and less direct exposure. Avoid sunbathing between 10 am and 2 pm, when the sun's rays are strongest.
2. 2Cover exposed skin with clothing and wear a wide brimmed hat that protects the face and neck.
3. 3Apply sunscreen that protects against both UVA and UVB to all uncovered skin. Reapply regularly, especially when going in and out of water.
4. 4Protect children with clothing, a hat with neck protection and high factor sunscreen, such as SPF 50, on exposed areas.
5. 5Stop using tanning beds. Continue sun protection every day, including during cosmetic treatment and on cold or overcast days.

Sunscreen is one part of protection, not a replacement for shade and clothing. Together, these measures reduce the risk of sunburn, skin cancer and premature ageing, including age spots, sagging and wrinkles. Protection remains useful after damage has appeared because it limits further exposure rather than merely addressing the appearance of existing marks.7

What should you do if you are sunburnt?

Sunburn makes skin hot and painful, often with redness. Peeling can follow after a few days. Keep the area cool, apply moisturizer or aftersun cream, drink plenty of fluids and stay out of the sun as much as possible. Do not repeatedly touch the burn or burst blisters, because either can increase the risk of infection. Severe sunburn can leave skin more likely to burn again for several months.3

Painkillers can ease discomfort, but do not exceed the recommended dose. Ask a pharmacist or doctor about anti inflammatory painkillers such as ibuprofen, since suitability depends on age and other medical problems. If pain remains uncontrolled, see your doctor rather than taking extra medicine. Vomiting, fever and headaches after sun exposure can indicate sunstroke and need emergency assessment.3

Can existing sun damage be treated?

Moisturizer helps dry and flaky skin, a less ambitious job than deleting your outdoor history. Avoid strongly drying or heavily perfumed soaps. Regular, long term use of retinoid creams, alpha hydroxy acids or vitamin C can reduce dryness and may improve fine wrinkles and uneven pigmentation. These options address particular visible changes rather than every effect of sun exposure.56

A dermatologist can match treatment to the change you want to address.

Treatment often combines more than one approach because wrinkles, pigment and looseness are different problems, despite sharing one face. Topical care is a long term process. A dermatologist should assess your skin type, health and the changes present before choosing a procedure. Continued UV exposure can interfere with results and increase treatment side effects.2

Which changes need a doctor?

Check your skin regularly for suspicious growths or other changes. Arrange assessment for a growing lump, a sore that does not heal or a persistent dry, scaly patch. Actinic keratoses sometimes become squamous cell carcinoma, a type of skin cancer. Suspicious lesions can need a biopsy, where a sample is taken for examination. Have spots assessed before cosmetic removal: skin cancer can be mistaken for an age spot, and treating it cosmetically can delay the right care.125