Scientists trying to discover whether and how stress may lead to skin problems have found in studying mice that a stress-triggered hormone could worsen or even cause skin disorders such as psoriasis and eczema.

The scientists found that blocking the hormone called glucocorticoid -- which increases in stressful times -- resulted in better skin.

Knowing how glucocorticoids work could help scientists find ways to prevent human skin problems caused by psychological stress, said lead researcher Kenneth Feingold of the Veterans Affairs Medical Center, San Francisco and the University of California at San Francisco.

"Here you have things going on in your mind that affect what's going on in your skin," Feingold told LiveScience.

Eczema, or dermatitis, is an inflammation of the skin with many causes and forms. It causes swollen, reddened and itchy skin.

Psoriasis in its most common form involves raised, red patches or lesions covered with a silvery white buildup of dead skin cells, called scale. It affects between 5.8 and 7.5 million Americans.

Up to 30 percent of cases lead to psoriatic arthritis, which causes pain, stiffness and swelling in and around the joints.

The outermost layer of skin, the epidermis, is made up of dead skin cells, which form a permeability barrier to prevent water loss. Every day tens of thousands of these dead cells slough off as tiny flakes.

Cells at the bottom of the epidermis usually grow, migrate to the surface and change into skin cells to replace the lost flakes.

Previous research showed that psychological stress decreases cell growth and inhibits differentiation into skin cells.

Scientists subjected hairless mice to stress in the new study while either blocking the production of glucocorticoids or blocking the action of the hormone. Some mice weren't treated at all.

Stress was created by placing the mice in small cages in constant light with a radio playing for 48 hours. The two groups of mice treated with a type of glucocorticoid-blocker showed much better skin function compared with untreated and stressed mice.

Scientists hope the study will lead to a way to treat people who suffer these skin conditions, but there is still more research needed. Besides needing to test the effect in people, blocking glucocorticoids could have negative side effects that are worse than exacerbations of skin disorders.

The research is detailed in the December issue of the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology.

Source:Xinhua/Agencies