Sunburn: Why It’s More Than Just a Bad Day at the Beach — And When to See a Dermatologist for Sunburn

A red, sore back after a few hours in the sun can feel like a minor inconvenience. It isn’t. Sunburn is a visible sign of DNA damage in your skin, and understanding what’s actually happening beneath the surface — plus knowing when a burn needs professional attention — matters far more than most people realise.

What’s Actually Happening When You Burn

Sunburn is your skin’s inflammatory response to UV-induced DNA damage. UVB radiation injures the DNA inside skin cells; in response, the body triggers inflammation and begins clearing out the damaged cells — which is what produces the redness, heat and soreness of a burn.

The problem is what happens when this damage isn’t fully cleared. Repeated UV injury accumulates in skin cells over time, and enough accumulated DNA damage can allow cells to begin dividing abnormally — the starting point for skin cancer. Crucially, this risk isn’t limited to people who burn constantly: research consistently shows that even a handful of blistering sunburns, particularly in childhood or adolescence, meaningfully raises lifetime melanoma risk. Sunburn isn’t just cosmetic damage — it’s a marker of genuine cellular injury.

Prevention Still Matters Most

• SPF 30 or higher, reapplied every two hours (and immediately after swimming or sweating) — a single morning application doesn’t hold up through the day
• Wide-brimmed hats and UV-protective clothing, especially between 11am–3pm when UV is strongest
• Shade-seeking as a first line of defence, not an afterthought

Some of our team’s preferred SPFs include Heliocare, La Roche-Posay and Altruist — though the best sunscreen is ultimately the one you’ll actually reapply properly.

Heliocare, La Roche Posay, Altruist.

If You Do Get Burned

For mild-to-moderate sunburn:

• Cool the skin with lukewarm (not cold) baths or showers
• Simple, fragrance-free moisturisers and aloe-based gels can ease discomfort, even though the evidence for aloe vera’s healing benefits is mixed
• Over-the-counter pain relief can help with soreness
• Hydrate well — sunburn draws fluid to the skin’s surface and away from the rest of the body, and dehydration is a real risk with more extensive burns
• Avoid further sun exposure entirely until the skin has fully healed

When Sunburn Needs a Dermatologist — or A&E

Most sunburn can be managed at home. But certain signs mean it’s time to seek professional care rather than wait it out:

• Blistering over a large area of the body, particularly in children or older adults
• Fever, chills, nausea, dizziness or confusion alongside the burn — these can indicate sun poisoning or heat illness, not just skin inflammation
• Signs of infection: increasing pain, spreading redness, warmth, swelling or pus days after the initial burn
• Widespread blistering plus severe pain unresponsive to simple painkillers
• Sunburn in a child under 12 months old — always seek medical advice
• Any burn that isn’t improving after a few days, or where you’re simply unsure

Beyond the acute burn itself, a history of sunburn — especially several episodes over your lifetime — is one of the clearest reasons to have your skin checked regularly by a dermatologist, not just when something looks obviously wrong.

Know What You’re Looking For

Between appointments, get familiar with your own skin. See a dermatologist promptly if you notice:

• A new growth that’s pearly, translucent, brown, black or multi-coloured
• A mole, freckle or brown mark that’s changed in size, shape or colour
• A spot that persistently itches, bleeds, scabs or won’t settle
• A sore that hasn’t healed within three weeks

For moles specifically, the ABCDE rule is a useful guide:

• Asymmetry — one half doesn’t match the other
• Border — edges are irregular, notched or blurred
• Colour — uneven tone, or multiple shades of brown, black or pink
• Diameter — most melanomas are at least 6mm across, though smaller ones do occur
• Expert — if in doubt, get it checked. Don’t wait

The Bottom Line

Sunburn is never “just” sunburn. It’s evidence of real damage to your skin’s DNA, and repeated episodes are one of the strongest predictors of skin cancer later in life. Prevention is always better than cure — but if you have been burned, know the signs that mean it’s time to see a professional, and make regular skin checks part of your routine, particularly if sunburn is part of your history.

Concerned about a mole, a burn that isn’t healing, or simply due a skin check? Our dermatologists have decades of combined experience in skin cancer diagnosis and prevention.

Book a consultation at No. 23 Skin 23 Ansdell Street, Kensington, London W8 – book online here, or call us on 02039411815.

Have a happy (and safe!) summer in the sun.

Dr Cherry Armstrong
Medical Director
Specialist Dermatology Doctor (who has been checking skin for more than 20 years…)
Cofounder

No. 23 Skin

02039411815

hello@23skin.co.uk

Disclaimer: this blog post is for informational purposes only. It should not be considered a substitute for professional medical advice. Always consult with a qualified healthcare provider for personalised recommendations and treatment.