A type of nerve cell that appears to be responsible for itching has been identified for the first time by US scientists, holding out the prospect of treatments to soothe the skin against irritations.

Experiments on cats' spinal cords at the Atkinson Pain Research Laboratory in Phoenix, Arizona, have found a series of neurons that fire only when the cats' skin is exposed to histamine, a powerful itch-inducing agent.

The study, reported in Nature Neuroscience, is the first to identify a nerve pathway by which the itching sensation is transmitted, and solves a mystery that has long confounded neurologists. While scientists have been aware for some time of specific neurons which transmit painful stimuli, a mechanism for the feeling of an itch has been elusive.

The findings have yet to be replicated in humans, but researchers are hopeful that a similar discovery might lead to better palliative and preventative treatments for itching. Such a drug would be helpful to patients who suffer from 'therapy-resistant itch', which often results from conditions such as dermatitis, liver disease, chronic kidney disease and HIV infection.

Martin Schmelz, of Erlangen University, Germany, said the research gave significant hope for new therapies.

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