A commonly-prescribed steroid can help people recover from the effects of a disfiguring facial condition, researchers in Dundee have found.
George Clooney has been affected by Bell's Palsy
A major study of Bell's Palsy found 95% of sufferers who were treated early with prednisolone completely recovered within nine months.
The nerve condition can result in paralysis on one side of the face.
It affects one in 60 people during their lifetime and can strike almost anyone at any age.
Bell's Palsy disproportionately affects pregnant women and people with diabetes, flu, colds and other upper respiratory ailments.
High-profile sufferers have included George Clooney and Pierce Brosnan.
The cause is a mystery, but the condition is widely treated with expensive anti-viral drugs.
However, the study claimed that the relatively cheap steroid prednisolone was the "best treatment".
Researchers said it had "significantly" better recovery rates than the anti-viral agent acyclovir, which they claimed "had little benefit".
The team found that early treatment with prednisolone offered complete recovery to 83% of patients after three months, and 95% after nine months.
Professor Frank Sullivan, who led the study, said the discovery would make a "real difference" to sufferers.
He said: "The present situation sees a mixture of different treatments given to patients, from steroids to anti-virals to not giving them anything.
"Around 80% of people get better without any treatment, but our findings significantly improve on that.
"What this study gives us is clear-cut evidence that early treatment with steroids offers by far the best results for complete recovery."
The condition was first identified by Scottish clinician Sir Charles Bell in the 19th Century.
It affects the facial nerve which enables people to smile and close their eyes.
Sufferers are affected by a sudden paralysis, characterised by the swelling of the facial nerve located in its bony canal in the skull.
Prof Sullican said: "What we have found is that prednisolone can reduce that swelling, so that the nerve can get back to working normally.
"Unfortunately it would appear that in around 5% of cases the damage caused to the nerve is more permanent and therefore complete recovery is not possible with currently available treatments.
"Early treatment of the condition, with steroids, is the key for patients."
The study was led by Dundee University, with support from other Scottish universities at Aberdeen, Edinburgh and Glasgow and GP services around the country.
The findings have been published in the New England Journal of Medicine.