How to protect your skin from the sun with Dr Mary Sommerlad

What does SPF mean?

SPF stands for Sun Protection factor and gives an indication of how much longer an individual can stay in the sun without being burnt by UVB waves. An SPF of 30 means your skin takes thirty times longer to burn/ develop redness than without the SPF.

What is a UV star rating?

UVA star ratings give an indication of how much protection from UVA waves, the waves that can penetrate glass and water and are associated with developing pigmentation issues and wrinkles, the sunscreen gives. The rating is out of 5 stars; the more stars, the more UVA protection. The rating was developed by Boots the chemists and applied to all sunscreens stocked by Boots. If you buy a sunscreen abroad, you may not see a star rating but instead a “PA” rating based on + symbol and is rated out of four, the higher the pluses, the more UVA.

What is melanin?

Melanin provides pigmentation to skin and hair. It provides protection from UVA, UVB and visible light by absorbing the energy from these waves. It protects against damage from reactive oxygen species 

Is sunscreen alone enough to protect from sun damage?

No, sunscreen is just one part of protection from sunburn. In addition to sunscreen, wear a wide brimmed hat, sunglasses with uv protection, long light sleeves, stay in the shade and avoid deliberate sunbathing 

Which sunscreen would be best for someone with Eczema/ Atopic Dermatitis? 

Look for sensitive formulations that are hydrating and contain ceramides. Niacinamide is also worth trying as it is soothing

Which sunscreen would be best for someone with sensitive skin?

Look for hydrating sunscreens suitable for sensitive skin. In the past we would recommend full mineral sunscreen but now chemical sunscreens are less irritating 

Which sunscreen would be best for someone with freckles?

Look for a sunscreen with antioxidants and visible light/ blue light 

Can dark skin get sunburnt and do people with dark skin need to use sunscreen?

Yes, any skin colour can burn in the right conditions. Melanin gives our skin its pigmentation but is also a form of naturally occurring sun protection. Research findings are varied but roughly state that having black skin gives an approximate sun protection factor of SPF 13- 15 compared to white skin. Increased protection from sunburn however does not mean complete protection from sunburn and in the right conditions (eg. Mediterranean summer weather) even the deepest skin tones can burn if sun protection measures are not followed.

Furthermore, those with olive, brown and black skin tones are more susceptible to UVA and visible light induced pigmentation problems such as Melasma and Post Inflammatory Hyperpigmentation (PIH). In these situations the skin may not burn but the pigmentation may become patchy.

My advice to those with skin of colour is to use sunscreen with good UVA coverage and with visible light coverage if they have Melasma or PIH in addition to avoiding sunbathing, staying in the shade during peak UVB times (11am until 3pm) and wearing a wide brimmed hat.

If you identify as having skin of colour but burn easily or have freckles or have a parent of white European heritage, ensure your SPF is also high at SPF50.

Research has now demonstrated that Vitamin D can still be generated despite using SPF50 in Sunshine; in the UK there are Nationwide guidelines on taking oral vitamin D replacement during the winter months when UVB is not strong enough to make Vitamin D.

What are your key take away messages about staying safe in the sun.

• Sunscreens are very sophisticated formulas to reduce damage caused by UVB,UVA and high energy visible light. Always reapply every two hour and be mindful about expiration dates.

• Sunscreen is most effective as part of sun protection routine including physical protection in the form of wide brimmed hats, sunglasses, avoiding sunbathing and staying in the shade.

• There will be a sunscreen that suits your skin, you may just have to look around.

• Tinted sunscreens that contain iron oxide are crucial to reduce visible light exposure which is important in Melasma.

If you have got sunburn blisters, how should they be treated?

Consider this similar to a thermal burn. Deflate but do not de- roof the blisters. Gently clean the skin the apply a thick, soothing barrier cream avoid sunbathing and apply sunscreen and keep affected skin covered. Expect residual hyperpigmentation such as freckling in the site where the blisters were sustained.

Dr Mary Sommerlad, Consultant Dermatologist and British Skin Foundation Spokesperson

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