Researchers have uncovered new clues to help understand how psychological stress can aggravate skin allergies.

The stress disrupts immune functions and interferes with the body's inflammatory responses, they found in studies in mice.

Specifically, psychological stress reduces the ability of specialized immune cells called anti-inflammatory PD-L2-positive macrophages to clear dead cells at the allergy site, according to a report in The Journal of Allergy and Clinical Immunology.

The accumulation of dead cells in the lesions leads to increased infiltration of immune cells called eosinophils, worsening the allergic response, the researchers said.

“This study is the first in the world to demonstrate that stress... disrupts macrophage function, which normally helps suppress allergic reactions, thereby intensifying allergic responses,” study leader Dr. Soichiro Yoshikawa of Juntendo University Graduate School of Medicine in Japan said in a statement.

The impact of psychological stress on immune cells appears to be long-lasting and can affect macrophages produced by the immune system later on, the researchers also found.

“This phenomenon, referred to as ‘stress memory,’ implies that severe stress leaves a lingering imprint on immune cells, influencing their function and contributing to disease development,” Yoshikawa said.

Avoiding stress altogether would be the ideal solution to prevent immune cell dysfunction, the researchers noted. Since that is not always possible, understanding the molecular mechanisms behind stress memory may pave the way for treatments that reverse the effects.