A skin test could help detect and research conditions including Alzheimer’s and Parkinson’s diseases, a new study has suggested.

Doctors from the Central Hospital at the University of San Luis Potosi, Mexico, studied 53 volunteers with forms of dementia to analyse skin samples for differing amounts of certain proteins compared with 12 healthy people.

The researchers reported skin biopsies from those with Alzheimer’s and Parkinson’s had higher levels of the protein phospho-tau compared with healthy people, while Parkinson’s sufferers also had higher levels of alpha-synuclein protein.

The preliminary results, doctors said, mean skin could be a useful way of detecting the diseases.

There is yet to be a definitive diagnostic test for dementia and there are calls for more people to take part in research.

Simon Ridley, head of research at Alzheimer’s Research UK, the UK’s leading dementia research charity, said: “These new findings are yet to be published in full and it is too early to say whether this preliminary study will lead to a new way of identifying people with Alzheimer’s disease and Parkinson’s.

“This research would need to be repeated in much larger groups of people to determine whether this method could be used in future to aid diagnosis.

“Skin biopsies are already proving useful in dementia research in other ways, for example at Alzheimer’s Research UK’s Stem Cell Research Centre.

“Human nerve cells can be grown in a dish from ‘reprogrammed’, donated skin cells to create a model of Alzheimer’s disease for research.”