Stress a factor in allergic reactions

BOSTON, Aug. 15 (UPI) -- Stress and anxiety can worsen allergic reactions -- especially the next day, U.S. researchers said.

The next-day change, called a "late-phase reaction" -- is important because it signals an ongoing and strengthening response to the allergens, and even suggests sufferers may react strongly to other stimuli that previously did not cause an allergic reaction.

Ohio State University researchers measured the size of wheals -- raised, itchy areas of skin that are a sign of allergy -- raised by standard skin prick tests in 28 men and women with a history of hay fever and seasonal allergies as they were exposed to psychologically stressing situations.

"The wheals on a person who was moderately anxious because of the experiment were 75 percent larger after the experiment, compared to that same person's response on the day when they were not stressed," study co-leader Jan Kiecolt-Glaser said in a statement.

"But people who were highly anxious had wheals that were twice as big after they were stressed compared to their response when they were not stressed. These people were four times more likely to have a stronger reaction to the skin test one day following the stress."

The findings were reported at the annual meeting of the American Psychological Association in Boston.