Doctor Gordon Dougal has helped to pioneer a device to treat the irritating effects of cold sores.

His hand-held machine has been available for £45 over the counter since 2001.

But the NHS has now made it available under prescription at £6.80 from GPs.

This is the first time the NHS has made a cold sore device available on prescription, as opposed to pills and potions.

Dr Dougal, a GP at Peterlee's Urgent Care Centre and William Brown Centre, said: "It is the very first time the NHS has approved a medical device to compete directly with pharmaceutical treatment.

"It is listed as a prescribed item for GPs and obviously they will evaluate the cost effectiveness of the product.

"If you get one cold sore a year then it is not going to be worth it, but if patients are getting three, four, or five, it is going to save practices a lot of money."

The Virulite Cold Sore Machine is a hand-held battery-powered device, which uses a specific beam of light to spur the immune system into action.

Patients point the light at the cold sore for three minutes, three times a day.

Dr Dougal said clinical tests showed an untreated cold sore took eight-and-a-half days to heal.

But patients who used the device were cured in an average of four-and-a-half days.

"By spurring the immune system, it accelerates the healing, so you can treat the cold sore at any time," said Dr Dougal.

The 50-year-old has spent the past 12 years developing the gadget as a director of Newton Aycliffe-based company Virulite.

The company has already sold around 30,000 devices over the counter.

And boffins at Sunderland and Durham University are now trying to develop similar machines for other treatments.

Helen Kendall, pharmaceutical services manager for the NHS, said: "We have got all sorts of devices for different conditions, but this is the first time we have approved anything for cold sores."