Sufferers find socializing difficult because of the appearance of their skin and some develop a specific form of arthritis linked to psoriasis.

But now researchers at Newcastle University have found an ointment used to treat symptoms actually kills off the cells that cause the condition.

Professor Nick Reynolds and Dr. Mark Birch-Machin, of the Skin and Environmental Interactions Research Group in the School of Clinical and Laboratory Sciences, believe this discovery is a major step to enabling the design of better treatments for psoriasis.

'A Lot of Things I Can't Do'

John Young, 47, who has suffered from the condition since he was nine, welcomed the research. "It's excellent news and I hope they'll go onto to find a cure," he explained.

"Sometimes I get it really bad and I don't want to go out anywhere or see anyone.

"There are a lot of things I can't do, like go swimming or play sport.

"It's more itchy than painful, but sometimes on my scalp when it gets really thick if I comb my hair it will bleed."

John, lives in Chapel House, Newcastle, with partner Sharon, 39, a psoriasis nurse he met during hospital treatment, their son Jack, nine months and Sharon's daughter Jade, 12.

"Sharon does a lot of my treatments for me because of her training which is a big help," John explained.

"But I've also developed arthritis because of the psoriasis which gives me a lot of pain in my joints, I actually need a knee replacement."

Ointment Derived from Araroba Tree

Prof. Reynolds and Dr. Birch-Machin studied the effects of dithranol, an ointment applied to the surface of the skin. The ointment is derived from the araroba tree, found in the rain forests of the Amazon. In India, the same substance is known as Goa powder.

"Dithranol is a very effective treatment for episodes of psoriasis and it has been around for a long time, since the early 1900s," explained Prof. Reynolds.

"By studying the action of the drug, we wanted to gain a better understanding of how it works, to give us an insight into the mechanism of the condition."

Laboratory studies showed dithranol very quickly targeted skin cells' mitochondria (the part of a cell from which it draws its energy) causing the cells to die within 48 hours of using the ointment.

The results of the Wellcome Trust-funded study are published in the Journal of the Federation of American Societies for Experimental Biology.