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Sunscreen

A substance that helps protect the skin from the sun's harmful rays. Using lotions, creams, or gels that contain sunscreens can help protect the skin from premature aging and damage that may lead to skin cancer.

PubMed Health Glossary
(Source: NIH - National Cancer Institute)

About Sunscreen

Put on broad spectrum sunscreen with at least SPF 15 before you go outside, even on slightly cloudy or cool days. Don't forget to put a thick layer on all parts of exposed skin. Get help for hard-to-reach places like your back. And remember, sunscreen works best when combined with other options to prevent UV damage.

How sunscreen works. Most sun protection products work by absorbing, reflecting, or scattering sunlight. They contain chemicals that interact with the skin to protect it from UV rays. All products do not have the same ingredients; if your skin reacts badly to one product, try another one or call a doctor.

SPF. Sunscreens are assigned a sun protection factor (SPF) number that rates their effectiveness in blocking UV rays. Higher numbers indicate more protection. You should use a broad spectrum sunscreen with at least SPF 15.

Reapplication. Sunscreen wears off. Put it on again if you stay out in the sun for more than two hours and after swimming, sweating, or toweling off.

Expiration date. Check the sunscreen's expiration date. Sunscreen without an expiration date has a shelf life of no more than three years, but its shelf life is shorter if it has been exposed to high temperatures.

Cosmetics. Some makeup and lip balms contain some of the same chemicals used in sunscreens. If they do not have at least SPF 15, don't use them by themselves. CDC - Centers for Disease Control and Prevention

What works? Research summarized

Evidence reviews

Sun protection (including sunscreens) to prevent basal cell carcinoma and cutaneous squamous cell carcinoma of the skin

The aim of this Cochrane Review was to find out if using topical sunscreen and physical barrier methods (such as sun‐protective clothing, hats, sunglasses, and the active search for shade when outdoors) compared with no specific precautionary activity prevented the development of basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) of the skin in adults and children.

Sunscreen use and melanocytic nevi in children: a systematic review

We conducted a systematic review of the association between melanocytic nevi (MN) in childhood and sunscreen use. A bibliographic search was conducted between November 2008 and January 2009 using the following key words on MEDLINE and EMBASE: child*, in combination with naevi, nevi, naevus, nevus and sunscreen, sun protection. We also used Medical Subject Headings [sunscreening agents], or [radiation protection] with [nevus, pigmented]. A first screening was done on title and abstract reading. Randomized trials and cohort and cross-sectional studies analyzing the relationship between the use of sunscreen and MN in children were selected. Three reviewers abstracted data from each article. The three sets of results were compared for concordance and rereviewed if necessary. Fifteen articles were included (20,743 children). The studies were not consistent in terms of the ages of the children, MN count methods, or sunscreen use assessment. Owing to this heterogeneity, we were unable to pool the studies and conduct a meta-analysis. Twelve studies did not report that the use of sunscreen had a protective effect against MN development. Three studies reported a lower MN count when sunscreen was applied. This systematic review underlines the methodologic differences between studies. Eight of 15 studies reported a positive association between sunscreen application and MN count. Differences in MN counts, overexposure to sun, and inadequate sunscreen application on fair-skinned children could explain the disparity in the results. There is still no evidence of a protective effect of sunscreen against MN development in children.

Sunscreen use and the risk for melanoma: a quantitative review

This meta-analysis of 18 case-control studies found no link between sunscreen use and an increased risk of melanoma. The authors used an appropriate methodology, but did not explore how assumptions about missing data might have affected the results. The findings should be interpreted with caution because the included studies were of low quality, used older sunscreen reparations, and had inadequate measures of sunscreen use.

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Summaries for consumers

Melanoma: How can you avoid too much sun?

Sun protection is something we can influence, so protecting yourself from the sun is considered to be the main thing you can do to prevent skin cancer. Children are more sensitive to sunlight than adults and need special protection from direct sun and sunburn. Ideally, protection from sunlight means avoiding too much UV-A and UV-B radiation. The sun’s rays are at their most intense during the summer, between 10 in the morning and 4 in the afternoon. You can limit your level of exposure to the sun by doing the following things: Avoid the midday sun during the summerSeek out shade, especially around noonUse a parasol and wear the right clothing and a hatWear sunglasses that offer UV protectionDo not use tanning beds or UV lampsUse sunscreen that has UV-A and UV-B protection and a high SPF (but shade or protective clothing are more effective) You can find helpful tips for parents to help protect their children from the sun in our information “Children and sun.”

Sun protection (including sunscreens) to prevent basal cell carcinoma and cutaneous squamous cell carcinoma of the skin

The aim of this Cochrane Review was to find out if using topical sunscreen and physical barrier methods (such as sun‐protective clothing, hats, sunglasses, and the active search for shade when outdoors) compared with no specific precautionary activity prevented the development of basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) of the skin in adults and children.

Children and sun – Practical information for parents

Most parents know that it is important to be careful when going out in the sun with their children – at least in theory. But in practice, it is often a struggle to get children to put sunscreen on, play in the shade or wear a sun hat. We have put together some ideas that might help you make sun protection part of your everyday routine.

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More about Sunscreen

Photo of a young adult woman

Also called: Sunscreen agent, Sunscreening agent, Sunscreen preparation, Sunscreening preparation

See Also: Skin Cancer: Prevention, Sunburn

Other terms to know:
Skin, Ultraviolet Radiation (UV Radiation)

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