Scalp sunburn: the burn people forget

You remembered sunscreen on your face, arms and the back of your neck. Then, that evening, a stripe along your part starts to sting, or the top of your head feels hot to the touch. Scalp sunburn is one of the most common burns people forget to prevent, partly because hair makes the skin underneath feel protected. It isn’t, at least not everywhere.

Why the scalp burns so easily

The top of your head faces the sun more directly than almost any other part of your body, especially around midday when the sun is highest. Hair blocks a lot of that light, but only where it’s dense. The weak spots are predictable:

• Your part line, a narrow strip of bare skin that faces straight up.
• The crown, where hair often swirls and thins.
• The hairline and temples, especially if they’re receding.
• Any thinning or bald areas, whatever the cause.
• Short haircuts and fresh braids or cornrows, which expose rows of scalp.

The Skin Cancer Foundation points to exactly these areas, the part, thinning or balding spots and the hairline, as the places that need protection.

In Canada, Health Canada says the UV index can reach 3 or higher between about 11 a.m. and 3 p.m., and recommends sun protection whenever the index is 3 or more, even on cloudy days. A long summer afternoon at the lake, a round of golf or a day of gardening easily adds up to a burn on unprotected scalp.

Hats: the easiest protection

A hat covers the whole scalp at once, doesn’t need reapplying and doesn’t make your hair greasy. The Skin Cancer Foundation calls hats the primary defence for the scalp, and Health Canada recommends a wide-brimmed hat made from breathable fabric.

What makes a hat work well:

• A tight weave. Some hats are labelled with a UPF (ultraviolet protection factor); the Skin Cancer Foundation suggests UPF 50+.
• A wide brim. A baseball cap covers the top of your head but leaves your ears and the back of your neck exposed. A brim all the way around protects more.
• Breathable fabric, so you’ll actually keep it on in the heat.

Sunscreen for the scalp

When a hat isn’t practical, for swimming, sports or just because, sunscreen fills the gap. Health Canada’s advice for any exposed skin applies to the scalp too:

• Use a broad-spectrum sunscreen with SPF 30 or higher, meaning it protects against both UVA and UVB rays.
• Choose water-resistant if you’ll be sweating or swimming.
• Apply at least 15 minutes before going out.
• Reapply at least every two hours, and more often after sweating, swimming or towelling off.

The trick with the scalp is getting sunscreen onto skin rather than hair. The Skin Cancer Foundation suggests applying it when your hair is completely dry, directly onto the part, any thinning or bald spots and all around the hairline. Different formats suit different situations:

• Sticks glide easily along a part line or hairline without leaving a chalky film.
• Sprays can be handy for larger thinning areas; part your hair so the spray reaches the skin.
• Lotions work well on a bald or shaved scalp.
• Mineral sunscreens, with zinc oxide or titanium dioxide as the filters, are an option if chemical filters sting your skin.

Hair products that claim UV protection for the hair itself are designed to protect colour and strands, and the Skin Cancer Foundation notes they’re less effective than regular sunscreen for the skin underneath.

If your scalp does burn

A burned scalp is red, tender, hot and sometimes tight or itchy. A few days later it often peels, and those flakes can look a lot like dandruff. The American Academy of Dermatology’s general sunburn advice applies:

• Take cool showers, and pat your head dry rather than rubbing it.
• Use a gentle moisturizer, ideally with aloe vera, on the burned skin while it’s still damp.
• Drink extra water, since a sunburn draws fluid to the skin’s surface.
• Don’t pop any blisters; they protect the skin while it heals.

On the scalp, it also helps to skip hot blow-drying and flat irons for a few days, wash with lukewarm water and a mild shampoo, and avoid tight ponytails or braids that pull on sore skin. Keep the area covered outdoors until it heals.

The NHS advises getting medical help promptly if sunburned skin is blistered or swollen, if you have a high temperature or feel hot, cold or shivery, or if you feel tired, dizzy or sick, have a headache or muscle cramps. Those can be signs of heat exhaustion. Babies and young children with sunburn should always be seen.

Skin cancer on the scalp

Repeated sun exposure over the years raises the risk of skin cancer anywhere, and the scalp is no exception. The problem is that scalp skin cancers are easy to miss. You can’t see the top of your own head, and hair hides small spots.

A 2023 study in the Journal of Clinical Medicine looked at 152 melanomas of the head and neck. The 35 on the scalp were mostly in older men with signs of long-term sun damage, and they were thicker at diagnosis and came back far more often than melanomas elsewhere on the head and neck. The authors recommend regular scalp checks, especially for older men with a lot of sun exposure, and point out that hairdressers are well placed to spot changes.

What you can do:

• Include your scalp in a monthly skin check, which the Skin Cancer Foundation recommends. Use a hand mirror, a hair dryer on the cool setting to part your hair, or ask someone to look.
• Ask your hairdresser or barber to tell you if they notice a new spot, sore or growth.
• Show your doctor any spot that’s new, changing, bleeding, crusting or not healing.

Protecting your scalp, in short

Scalp sunburn is easy to forget and easy to prevent. A wide-brimmed, tightly woven hat is the simplest fix; for the part line, crown and thinning spots, a broad-spectrum SPF 30 or higher sunscreen applied to dry hair and reapplied every two hours covers the rest. And because skin cancers on the scalp are often found late, make your scalp part of your regular skin checks, and get anything new or changing looked at.