The seminal fluid contains a protein foreign to the body of a woman, and theoretically an allergic reaction may occur to it. It manifests itself as swelling, redness, itching, irritation of the vaginal mucosa and is directly related to unprotected intercourse (allergic reactions to latex (condoms) and lubricant creams also occur). Moreover, this reaction can be on the ejaculate of one partner, and with the other there will be full compatibility.

To make an accurate diagnosis, it is necessary to exclude diseases (bacterial and viral), sexually transmitted; dysbacteriosis; anatomical features of the location of the opening of the urethra and vagina, leading to trauma during intercourse – that is, you need to be examined by a gynecologist, urologist, allergist and make special tests to identify the allergen.

In the treatment of this problem, specific immunotherapy https://en.wikipedia.org/wiki/Immunotherapy is used, as well as a cream containing an antihistamine (anti-allergic) component. Sometimes the immunological incompatibility of sperm with the vaginal environment even becomes the cause of infertility.