Sunburn
Sunburn is an injury to the skin from ultraviolet light. The redness and pain are the body clearing away damaged cells, which is why they arrive hours after the exposure rather than during it. The skin heals in about a week. Some of the DNA damage underneath does not.
Key facts
Sunburn at a glance.
Typical signs
Hot, sore skin after sun
Common locations
Sun-exposed skin
Expected course
Mild burns heal in about a week
Treatment options
Cooling, moisturizer and pain relief
What is it?
Top things to know about Sunburn
- It is an ultraviolet injury. Sunburn is inflammatory skin damage caused by excessive ultraviolet exposure.
- Symptoms follow exposure. Warmth, tenderness, swelling and color change develop afterwards; severe burns may blister.
- Cool weather still counts. Ultraviolet damage occurs even when it feels cool or redness is hard to see.
- Unusual reactions have causes. A severe burn after little sun can reflect a photosensitizing medicine or condition.
What it looks like
What Sunburn looks like
Sunburn is skin damage from ultraviolet light. It usually appears a few hours after sun exposure and peaks at 12 to 24 hours. Mild sunburn causes redness, warmth and tenderness. More severe burns can swell and blister. As it heals over the following days, the skin peels and may itch. Every sunburn raises the long-term risk of skin cancer.
Redness
Hot, tender skin in sun-exposed areas.
Blisters
Fluid-filled blisters in severe burns.
Peeling
Skin flaking as it heals.
Where it shows up
The sites depend on which skin was exposed. These are examples, not a fixed distribution.
Face
Facial locations.
Chest
Locations on the front of the upper trunk.
Upper back
Locations on the upper back.
Upper arms
Locations on the outer upper arms.
Arms
Locations along the forearms.
On different skin tones
Sunburn on different skin tones
Everyone can get sunburned. On lighter skin, sunburn looks bright red. On brown and Black skin, it may look darker, gray or not change color at all, so it is often noticed by feel: tightness, warmth, pain or peeling. Darker skin has more natural protection, but it still burns and still benefits from sunscreen.
What happens in Sunburn?
Excess ultraviolet exposure injures skin cells and triggers inflammation. Increased blood flow and swelling cause soreness and warmth, and damaged surface cells may later peel away.
- Damaged cells are shed: The skin may peel as it recovers.
- UV damages skin cells: Excess ultraviolet light injures cell components.
- Inflammation develops: Chemical signals increase blood flow and swelling.
Causes and triggers
What causes Sunburn
Causes
Why it happens
Sunburn is damage to skin cells from ultraviolet light. The redness and pain come from the inflammation that follows.
Fair skin, red hair and freckles mean less natural protection from melanin.
Risk factors
Raise the odds
- Fair skin
- Some medicines
- Retinoids and acids
- Young children
Triggers
Bring it on or make it worse
- Midday sun (Well established)
- Tanning beds (Well established)
- High altitude (Strong link)
- Water, sand and snow reflection (Strong link)
When it usually starts
When it usually starts
Sunburn
Can occur at any age after enough ultraviolet exposure.
Daily care
Daily care for Sunburn
Get out of the sun and stay out
More exposure deepens the injury.
Drink more fluid than usual
Burned skin pulls fluid out of circulation.
Leave blisters intact
If one opens, keep it clean, with petrolatum and a non-stick dressing.
Loose cotton clothing
Less rubbing on inflamed skin.
Broad-spectrum sunscreen, SPF 30 or higher
Use generously and reapply every two hours outdoors and after swimming or sweating.
Clothing, a wide-brimmed hat and shade
More reliable, because they do not wear off.
Planning around midday
Limit midday sun and seek shade when ultraviolet levels are high.
Cool compresses
Use a cool, damp cloth for comfort; never apply ice directly to burned skin.
Moisturizing
Apply a plain, fragrance-free moisturizer to slightly damp skin to ease dryness.
An anti-inflammatory painkiller early
Better in the first hours than on day two. If you are pregnant or breastfeeding, ask the doctor managing your pregnancy which pain relief is appropriate.
Low-strength hydrocortisone cream
One percent takes the edge off small areas for a few days.
Ask about sun precautions for photosensitizing medicines; do not stop them yourself
A normal amount of sun produces an abnormal burn. Ask your prescriber about precautions, not stopping anything.
Avoid: Not using enough sunscreen
Most people apply a quarter to half of what testing assumes.
Avoid: Not reapplying
About every two hours, and after swimming or sweating.
Avoid: Assuming cloud is protection
Much of the ultraviolet passes through it.
Avoid: Reflected light from water and snow
It reaches skin that shade would cover.
Avoid: Midday sun, altitude and the equator
The same time in the sun does more damage.
Avoid: Staying in water because it feels cool
Water barely filters ultraviolet light.
Avoid: Lime juice, hogweed and plant saps
Exaggerated burns in streaks where the sap landed.
Avoid: Going back out on burned skin
Damaged skin has no protection left.
Avoid: Popping blisters
Opening them invites infection and can turn a clean burn into a scar.
Avoid: Hot showers, scrubbing and exfoliating
Heat and friction increase pain and redness.
Avoid: Numbing sprays
Benzocaine and lidocaine cause allergic rashes on inflamed skin.
Avoid: Not drinking enough
Dehydration is why people feel unwell after a day in the sun.
Avoid: Tanning beds
The same injury, delivered deliberately.
Treatments
Treatments for Sunburn
Ibuprofen or naproxen
An anti-inflammatory painkiller works on the actual mechanism of a sunburn, which is inflammation, and it helps most when it is started in the first few hours rather than added on day two. Take it regularly for the first day or so rather than only when the pain peaks. If you are pregnant or breastfeeding, ask the doctor managing your pregnancy which pain relief is appropriate.
Hydrocortisone
One percent hydrocortisone can take the edge off a small, sore area for a few days. Use it on unbroken skin only, never on blisters or open areas, and not over large parts of the body. It is a mild help rather than a fix, and if the burn is big enough that you want to cover it all, that is a burn worth having looked at.
Numbing sprays and gels
Benzocaine and lidocaine sprays sold for sunburn cause allergic rashes on inflamed skin often enough that they are not worth using. The relief is short, and an allergic reaction on top of a burn is a considerably worse week. Cool compresses and an anti-inflammatory painkiller do the same job without that risk.
Aloe Vera
Cooling and pleasant on a burn, and it is what most people reach for first. The trial evidence that it does anything beyond that is thin. Keep it in the fridge if you like it, choose a plain gel without added fragrance or alcohol, and do not expect it to shorten anything. It is comfort, not treatment.
Petrolatum
Its job here comes later, on peeling skin and on any blister that has opened, where it stops the new skin drying and cracking and reduces the itch. Use it under a loose non-stick dressing rather than an adhesive one. It is not for the first day on an intact, hot burn, where a thick greasy layer traps heat and makes things feel worse.
Mometasone
A stronger steroid cream, sometimes prescribed for a few days on a severe burn that hydrocortisone has not touched. It reduces the inflammation and the soreness a little. It does not change how long the burn lasts or repair any of the damage underneath, and it goes on unbroken skin only, never on blisters or open areas.
Mupirocin
An antibiotic ointment for the specific situation where broken blisters have become infected, which shows as increasing redness, swelling, heat or pus. It is not for a plain burn and does nothing for one. If the infection is spreading beyond the burnt area, antibiotic tablets are needed instead.
Outlook
What to expect with Sunburn
The worst of a sunburn arrives after you have gone indoors. Nothing makes it heal faster - aftercare makes the week bearable and prevents complications, but does not undo the injury. The DNA damage does not fully reverse, and repeated burns, particularly in childhood and adolescence, contribute to actinic keratoses, squamous cell carcinoma, basal cell carcinoma and melanoma decades later.
- 1
Nothing visible · During exposure
No redness and often no discomfort, which is the whole problem with waiting to feel it.
- 2
Appearing · 2 to 6 hours after
Skin starts to look pink or darker and feels warm and tight. On deeper skin tones this is felt rather than seen.
- 3
Peak, and blisters · 12 hours to day 3
Redness, heat, tenderness and swelling peak, and the burning disturbs sleep. Deeper injury brings small blisters over the next day or two. Fever, chills, headache, nausea or weakness with a large burn means it should be assessed.
- 4
Peeling · Day 3 to 8
The damaged outer layer sheds in sheets. The new skin underneath is thin, pink and very sensitive to sun and products.
- 5
Settling · Week 2 onward
Discomfort resolves. Skin can look uneven, and dark patches may appear where the burn was. On deeper skin tones especially these take many months to fade, and further sun makes them last longer.
Complications
Complications to know about
Blisters that get infected
A blister means the injury went deeper into the skin. An intact blister is a sterile cover over an open wound, and popping one lets bacteria in and can turn a burn that would have healed cleanly into one that scars. Leave them alone. If one opens by itself, keep it clean, use plain petrolatum and a non-stick dressing, and get it looked at if the area becomes hot, swollen or starts oozing pus.
Heat illness and dehydration
A large burn is not only a skin problem. Fever, chills, headache, nausea, weakness, dizziness and intense thirst come from a big area of inflamed skin losing fluid alongside hours in the heat. It is often called sun poisoning, which it is not. Children and older adults reach this point sooner. It needs shade, fluids and, if there is confusion, fainting, vomiting or very little urine, same-day medical care.
Skin cancer decades later
This is the complication that never looks like one at the time. Repeated blistering sunburns, particularly in childhood and adolescence, are associated with a substantially higher risk of melanoma later, and ordinary cumulative exposure drives most other skin cancers. No amount of aftercare undoes it. It is why a pattern of burning every summer is worth a conversation, and why a history of repeated burns is a reason to arrange a skin check.
When to get help
When to get help
When to seek care
Get prompt help for extensive blistering, dehydration, fever or severe pain; babies and young children need a lower threshold for assessment.
Lookalikes
What else could it be?
Contact Dermatitis
A sunlight-related contact reaction may leave drips, streaks or handprints where plant sap touched the skin. Ordinary sunburn follows the areas exposed to sunlight.
Rosacea
Rosacea repeatedly flushes across the central cheeks and nose. Sunburn follows a particular sun exposure and can also affect exposed ears, forehead and jaw.
Cellulitis
Sunburn follows exposed skin and clothing lines. Cellulitis usually affects one area that keeps spreading and may cause fever or feeling unwell.
Questions
Questions you might be asking.
How long does a sunburn last?
Redness appears within two to six hours, peaks around twelve to twenty-four hours, and settles over three to seven days, with peeling toward the end. Blistering burns take longer and can leave marks for months. Nothing shortens it.
Can I stop it peeling?
Not really. Peeling is dead skin being shed; the damage is already done. Moisturizer reduces itching and cracking. Do not pull the flakes off - that exposes tender new skin.
Should I pop the blisters?
No. An intact blister is a sterile cover over an open wound and lowers the risk of infection and scarring. If one opens, keep it clean, use plain petrolatum and a non-stick dressing, and have it checked if the area becomes hot, swollen or oozes pus.
Does one bad sunburn really raise my skin cancer risk?
Each burn adds to a lifetime total rather than deciding anything on its own. Repeated blistering sunburns, particularly in childhood and adolescence, carry a substantially higher risk of melanoma. Ordinary cumulative exposure drives most other skin cancers.
Why did I burn so badly when I was barely in the sun?
Usually a medicine that increases sensitivity to ultraviolet light - some antibiotics, diuretics, anti-inflammatories, retinoids and others. Plant sap, especially lime juice, does the same in streaks, and recent peels or laser lower the threshold. Ask a pharmacist rather than stopping any prescribed medicine yourself.
Is a tan from a tanning bed safer than one from the sun?
No. A tanning bed delivers a concentrated dose of ultraviolet light and causes the same DNA damage. Using one before the age of 35 carries a notably higher risk of melanoma. The tan is the injury response, so no version of deliberate tanning avoids it.
Sources
Sources and further reading
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