Sex hormones put women at allergy risk

Female sex hormones called oestrogens can worsen allergic reactions in women, says a study.

"Women are more likely to suffer lethal allergic reactions because the female sex hormone makes the condition worse," says a Telegraph report, quoting the study by the National Institute of Allergy and Infectious Diseases in the US. Researchers found that oestradiol - a type of oestrogen - enhances the levels and activity of the chemical which drives life threatening allergic reactions in women.

One such condition is anaphylaxis - an allergic reaction triggered by food, medication or insect stings and bites. In experiments on mice, the team found that female mice experience more severe anaphylactic reactions than males. Oestrogen influences blood vessels, enhancing the levels and activity of an enzyme that causes some of the symptoms of anaphylaxis.

The researchers found that giving oestrogen-blocking treatments to female mice reduced the severity of their allergic responses to a level similar to those seen in males. The paper appeared in The Journal of Allergy and Clinical Immunology.