A new cream that can remove sun spots without the pain of conventional treatment has been developed by scientists.
The product, yet to be named, has proven in trials to work on the lesions which can turn cancerous, causing them to scab over and then drop off.
Finnish researchers found the cream, which needs the sunlight to work, can remove 80 per cent of a person’s sun spots within a week.
The product has proven in trials to work on the lesions which can turn cancerous, causing them to scab over and then drop off (stock of an actinic keratoses sun spot)
Patients can currently have their sun spots – known medically as actinic keratoses – removed by having them frozen off with liquid nitrogen.
However, pain is a known side-effect of cryotherapy, which turns a couple of the patches into blisters which then fall off on their own in a few weeks.
Creams that work in the same way already exist for people concerned about their sun spots – but often take much longer to kick-in.
Actinic keratoses, which can turn into skin cancer, are rough patches of brown skin caused by damage from years of sun exposure.
They are different from liver spots, which are known as solar lentigo and can also occur from spending too much time in the sun.
Officials estimate that around a quarter of people living in the UK have a sun spot. The figure is similar in the US but higher in Australia.
The new cream, based on aminolevulinic acid – already approved for use in cancer, was tested by a team at the University of Tampere.
It is yet to be approved in the UK – but the chemical is available for treating sun spots in the US and was given the greenlight in Europe in 2011.
Dr Janne Räsänen, study author, said the new cream can minimise pain and, therefore, allow patients to have more taken off in one go.
Patients seeking to remove their sun spots must sit outdoors for two hours while wearing the aminolevulinic acid-based cream.
The UV rays from the sun then react with the product to form protoporphyrin IX, which releases reactive oxygen species molecules.
Dr Räsänen and colleagues said this reaction then causes the cells in the sun spots to die and fall off, New Scientist reports.
Their study, published in the British Journal of Dermatology, compared two different creams on nearly 70 adults with sun spots.
The researchers found the aminolevunlic acid-based cream was more effective than methyl‐5‐aminolevulinate – and the participants denied it caused them any pain.
Professor Stephen Shumack, involved in other trials of the cream, said the aminolevunlic acid-based cream can work after being applied just once.
He compared it to fluorouracil cream, approved by the NHS and US drug regulators, which has to be applied daily for four weeks to work.
Professor Shumack, of Sydney University also said fluorouracil cream – known as Efudex in the US and Efudix in the UK – causes more irritation.
Commenting on how the cream works on the skin, Professor Shumack told New Scientist: ‘You look like you’ve had a bad sunburn for the first few days.
‘Then the skin gets scabby and crusted over and the sun spots peel off within a week. The skin looks a lot better afterwards – it becomes very smooth.’
Dr Adil Sheraz, consultant dermatologist and British Skin Foundation spokesperson told MailOnline: ‘Sun spots also known as actinic keratoses are pre-cancerous skin lesions that can present as scaly, skin coloured, brown or yellowish patches often on sun exposed areas such as the face, ears and back of the hands.
‘Creams are available that will need to be applied for up to four weeks without any light treatment and will clear sun related skin damage.
‘However, these can often be associated with significant redness, soreness and inflammation at the site of application.’