Alopecia and Scalp Skin Cancer: Why Sun Protection Matters

Hair loss doesn’t just change how your hair looks. It also changes how your scalp is exposed to the world—especially to the sun.

Most people are now good at protecting their face with SPF. But the scalp is often forgotten.

If you have any degree of hair thinning or hair loss, that matters more than you might think.

The part people don’t realise

Your hair normally acts as a natural barrier.

As it becomes thinner, more sunlight reaches the skin underneath—day after day, year after year. It’s not usually one big sunburn that causes a problem. It’s the slow, repeated exposure over time.

That cumulative exposure is what increases the risk of skin changes and, in some cases, skin cancer.

This is something I look out for routinely, and it’s often overlooked.

Why hair loss changes things

Hair loss itself doesn’t cause skin cancer.

But it does remove protection.

So if you imagine:

• the top of the scalp with thinning hair

• a parting that’s gradually widening

• or areas where the hair has disappeared completely

Those areas are quietly getting more sun than they used to.

And most people aren’t putting SPF there.

What I recommend:

This doesn’t need to be complicated.

1. A hat when it makes sense

If you’re out in the sun for a while—walking, gardening, on holiday—a hat is the simplest and most reliable protection.

2. SPF on the scalp

There are now sprays and mists designed for the scalp that don’t make the hair greasy or heavy. These work well on partings and thinning areas.

3. Be aware of the UV Index

Many of us with fair skin have sunburned on cloudy days in the past. The best way to know if you need SPF is not by looking out of the window, but by checking the UV forecast.

4. Be mindful of the time of day

You don’t need to avoid the sun completely. Just be mindful of longer exposure, especially in the middle of the day 11-3 or abroad.

Small habits here make a difference over years.

You may have seen something about PRP and cancer risk

A paper has recently raised the question of whether PRP (platelet-rich plasma) could in theory increase cancer risk when used on sun-exposed scalps.

I want to address that directly, because it’s the kind of thing that can sound worrying when taken out of context.

The concern is based on the idea that PRP contains growth factors—signals your body uses for healing and repair. Those same pathways are also involved in how cancers behave, so the question has been raised theoretically in a recent paper.

But at the moment, that’s where it sits:

a theoretical question, not something we’re seeing in real patients.

There’s no clinical evidence showing that PRP increases cancer risk in the scalp or elsewhere - joints, skin, dental and so many other applications. PRP has been used in other areas of medicine for many decades without any link to cancer.

In contrast, we do have strong evidence about one thing:

sun exposure is the main driver of skin cancer on the scalp.

So that’s where the focus should be.

How I approach this in clinic

If I’m treating someone’s scalp, I’m always thinking about the bigger picture.

That includes:

• looking carefully at the scalp beforehand

• making sure there’s nothing that needs checking - and check it if it does with our dermatologist

• and advising on simple sun protection going forward

It’s not about avoiding treatment—it’s about doing things properly.

The take-home

If you have hair loss, your scalp is more exposed than it used to be.

That doesn’t mean you need to worry—but it does mean it’s worth protecting.

A hat when you need it.

Some SPF where it’s thinning.

A little more awareness over time.

Those small things matter far more than most people realise.

If you’re not sure what you’re looking at on your scalp, or you’ve noticed any new or changing areas, it’s always worth getting it checked.”