Experts criticise sunscreen advice

Recommendations for people to use a minimum factor 15 sun cream are “not in the interests of public health”, UK experts have said.

In January, the UK National Institute for Health and Clinical Excellence published guidance saying people should wear broad spectrum (UVA and UVB) sunscreens with a minimum factor 15 sun protection.

But today, an editorial in the Drug and Therapeutics Bulletin urges a rethink, saying the recommendation is far too low and not based on how people actually use sun creams.

Factor 15 offers all-day protection only if it is applied thickly, at a thickness of 2mg/cm2, the experts said. This thickness is used by manufacturers as the standard test for SPF. However, the experts said people using sun creams usually apply much less than this - and also pointed out that sunscreen runs off the skin.

They said: “Using it ‘adequately’ is also costly, since whole-body coverage for a single application for an adult at 2mg/cm2 requires around 35ml of sunscreen.

“Applying this much at least every two hours, as Nice also recommends, would require a standard 200ml bottle of sunscreen every two to three days.

“In our view, the Nice advice on sunscreen use is not in the interests of public health.

“Products labelled with an SPF of 30 (together with a four or five-star rating to indicate broad-spectrum ultraviolet screening effect) will more reliably deliver adequate sun protection to most people who use sunscreens and would be sufficient to prevent sunburn under most circumstances.”

The experts argued that a “more logical solution” would be for manufacturers to change how they test sunscreens “so that it accurately reflect(s) the way people actually use sunscreens in real life.

“Then the SPF would really tell people what sun protection to expect.”

Ike Iheanacho, medical doctor and editor of DTB, said: “In DTB’s view, Nice’s recommendation to use sunscreens with an SPF as low as 15 is a blunder that overlooks the key evidence and is not in the best interests of public health. This advice needs urgent review and correction.”

The DTB advises that people with fair skin can safely expose their hands, arms, face or back to sunlight in the UK from April to September, for 15 minutes two or three times a week. Those with darker skin tones will need to stay out longer.

Figures show that more than two Britons under 35 are diagnosed with the deadliest form of skin cancer every day.

Rates of malignant melanoma have tripled among those aged 15 to 34 since the late 1970s, according to analysis by Cancer Research UK. Then, there were 1.8 cases of melanoma per 100,000 people in this age group, rising to 5.9 now.

It is thought sunbeds are playing a role in boosting cancer rates, together with not using sunscreen on summer holidays.

Mike Kelly, professor and director of the centre for public health excellence at Nice, said: “The Nice guidance referred to was not an assessment of which sun protection factor is optimal, but rather was concerned with the most effective ways of reducing skin cancer in England through provision of information, supply of resources and changes to the physical environment.

“It also sought to make clear that sunshine can be good for us, in that it provides a good source of vitamin D, and the opportunity to be physically active out of doors.

“We felt it was important, in producing this guidance, to maintain a balance – recognising on the one hand the very real dangers of skin cancer, but also remembering on the other hand that we should not extrapolate from research carried out in much hotter, sunnier climates than our own.

“We commissioned an expert report on the use of sunscreen in preventing skin cancer in England.

“According to this evidence, which was presented to the committee, SPF 15 should be sufficient as long as it is applied adequately.

“However, the guidance also acknowledges that to take account of people not applying sufficient quantities of sunscreen, SPF 30 was also recommended in an expert paper.”

The article comes as the Medical Defence Union (MDU), which insures doctors, issued a warning to GPs to be on the lookout for malignant melanoma, the most deadly form of skin cancer.

Over the past five years, it has been told of 134 legal cases involving patients with malignant melanoma.

Of these, 123 arose in primary care, where most (89 per cent) involved allegations of delayed or failed diagnosis.