Acute psychological stress promotes healing in three mouse models of skin irritation, a new study suggests.

Researchers from the San Francisco VA Medical Center studied mouse models of irritant contact dermatitis, acute allergic contact dermatitis, and atopic dermatitis. After exposure to irritants on a small patch of skin on one ear, one group of mice was returned to its regular cages, while another group was placed in a stressful situation (very small enclosures for 18 hours a day over the course of four days).

Stressed mice showed significantly reduced inflammation and faster healing in all three types of skin irritation, the researchers report. Healing was brought about by the anti-inflammatory effects of glucocorticoids produced by the adrenal glands in response to stress, they write.

When stressed mice were simultaneously given mifepristone, which blocks steroid action, all of the healing benefits of stress disappeared, the study showed.

“Under chronic stress, these same naturallynoccurring steroids damage the protective functions of normal skin and inhibit wound healing, but during shorter intervals of stress, they are beneficial for inflammatory disorders and acute injury in both mice and humans,” the team reports in the Journal of Investigative Dermatology.