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Sunburn, and what to do about it

April 13, 2020 / Duncan Fisher
Winter is over – but take it easy

So you’ve got a sunburn. Sorry about that. Welcome to warm weather. In some parts of the world, like the northern latitudes, getting a sunburn can be a surprise. In other parts, farther south, it’s almost a way of life.

You want to avoid sunburn, because it’s a great way to encourage skin damage, or scarier things, like skin cancer. It’s also miserable by itself. Burns hurt.

What is sunburn, exactly? And what can you do if you get it?

Here’s a little primer.


Sunburn isn’t the same as thermal burn. It’s a biochemical reaction to ultraviolet radiation. It’s a complex bundle of processes, that actually aren’t all the way understood yet. Sunburn elicits the manufacture of prostaglandin and cytokine proteins, that dilate blood vessels and summon inflammatory cells. That’s where the redness and the pain come from. Because it takes a few hours for this to happen, you don’t feel your sunburn until a few hours later. Sometimes cells are damaged enough that they die off, and peel away. (Other times there is DNA damage, which is ultimately the source of skin cancers.) Those dilated blood vessels, by the way, are why burned skin feels warmer than usual. It actually is warmer, slightly.

‘Sun poisoning’

In some parts of the world you hear about ‘sun poisoning’.

There actually isn’t any such thing. The sun can’t poison you.

What people mean usually is sunstroke, or as it’s called sometimes, heatstroke.

This isn’t a ‘stroke’ either. That word is a misnomer here. What it is, is a physiological reaction to overheating.

It can feel sort of like an infection. People get thirsty, dizzy, weak, or nauseated. Sometimes there are muscle cramps. If it’s really bad, the thirst may disappear, and sweating may stop.

Heatstroke is not trivial. When early signs appear, it’s time to get out of the sun, lie down, cool down, and start rehydrating. If it doesn’t resolve, or if symptoms get worse, it’s time for medical attention.


There is another syndrome people mean sometimes when they speak of sun poisoning. This is polymorphic light eruption. It’s a kind of photosensitivity that mostly young women get, in warm climates.

It can take various forms (which is what ‘polymorphic’ means), but generally it looks like little pink papules or patchy red skin, usually with itching, and sometimes with fever or malaise. It can go on for days. It can look a lot like lupus, though it isn’t lupus.

No one really knows what causes it. There’s probably a genetic predisposition, and it probably involves impaired T–cell function.

PMLE doesn’t require treatment, as a rule. It goes away in a week or so. Your doctor might offer topical cortisone if the itching is bad. The basic intervention is to stay out of the sun.

Treatment for your basic sunburn

So back to that sunburn, if that’s what you have. What do you do about it?

First, get out of the sun.

Then cool down with a shower or a damp cloth.

Put on a skin soother, like aloe vera.

Hydrate with a lot of water.

Get out the paracetamol if you’re stinging a lot.

Going forward, don’t cover your burn with petroleum jelly, and don’t put on ice packs.

If there’s blistering, don’t pop anything. That’s second-degree burn, and it needs to be left alone.

When it all starts to heal, it’ll itch. Try not to scratch it.

If it peels, let it. But try not to peel it off yourself.

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