Researchers at King's College London have devised a new method to quickly determine the number of moles on the entire body by counting the number found on a smaller body area, such as an arm, Medical Xpress reports.

The study is being published in the British Journal of Dermatology.

The mole count is one of the most pertinent indications for skin cancer. However, only 20 to 40 per cent of melanoma arising from pre-existing moles.

The risk of skin cancer is thought to increase by two to four per cent per additional mole on the body. However, the process of counting the total number of moles on the entire body is time consuming.

For the study, the researchers studied data from 3594 female Caucasian twins between January 1995 and December 2003 as part of the TwinsUK study protocol.

This study attempted to identify the most useful 'proxy' site for a full body mole count as well as the 'cut off' number of moles that can be used to predict those who are at the highest risk of developing skin cancer.

Scientists found that the count of moles on the right arm could predict the total number on the whole body. They also found that the area above the right elbow could predict the total body count of moles.

Lead author, Simone Ribero of the Department of Twin Research & Genetic Epidemiology said: "This study follows on from previous work to identify the best proxy site for measuring the number of moles on the body as a whole. The difference here is that it has been done on a much larger scale in a healthy Caucasian population without any selection bias and subsequently replicated in a case control study from a similar healthy UK population, making the results more useful and relevant for GPs.

"The findings could have a significant impact for primary care, allowing GPs to more accurately estimate the total number of moles in a patient extremely quickly via an easily accessible body part. This would mean that more patients at risk of melanoma can be identified and monitored."