Psoriasis patients learn to cope when others show disgust in response to their skin lesions by automatically shutting off a specific part of their brains, UK researchers report.

"In psoriasis patients, the brain appears to become 'accustomed' to facial expressions of disgust," said principal author Dr. Christopher Griffiths, dermatology professor and head of the Research School of Translational Medicine at the University of Manchester.

It has been previously shown that psoriasis patients can be very sensitive to signs of aversion from others and scan their environment for negative cues as people react to their skin lesions.

However, these new findings provide the first evidence that such behavior causes changes in their brains, Griffith said.

The investigators used a procedure called functional MRI to scan the patients' brain and visualize the insula, an area known to process facial expressions, in nine male patients with moderate or severe chronic plaque psoriasis and nine age-matched healthy volunteers. The subjects were 21 to 44 years old.

After being exposed to pictures of faces depicting disgust, fear or neutral expressions, psoriasis participants were found to have a specific 'attenuated response' detected in the insula when they perceived disgust.

According to Griffiths, this finding suggests that patients have to frequently cope with these expressions in others and eventually develop familiarity with such reactions. "It seems to be a learned response mechanism, which might help them to cope with the disease," he told Reuters Health.

Because of the limited size of the study, researchers were unable to detect a link between the extent of insula inactivation and severity of disease. They also do not know if this differential response returns to normal once psoriasis is completely cleared or if the phenomenon also occurs in patients with other disfiguring conditions, Griffith added. "We need bigger studies to assess that."

The work was presented last week at the 21st World Congress of Dermatology.