This explains A LOT - Women Allergic to Semen

LiveSciece.

I don't usually go here, but...it seems appropriate somehow.

Some women suffer from severe allergic reactions to male semen, often because of the male's diet, or sometimes it is specific to one partner. Women suffering form this allergy often (about half the time) suffer from other allergies.

"One study from the University of Cincinnati of 1,073 women who sought information on semen allergy concerning their symptoms found 130 had the allergy. In some women, the reaction occurs only with one partner while others are allergic to all partners."

I think it's probably even more common than they found from this study. You're talking over 12% from this one. I do appreciate the cure, though. Maybe they should ask for volunteers to assist the poor women.

"To desensitize a woman's immune system against semen, doctors can either apply diluted samples of semen to a woman's vagina every 20 minutes, gradually increasing the concentration over the course of several hours, or the women can receive allergy shots containing small amounts of semen over the course of several weeks. Both techniques require sex two or three times a week to train their immune system."

I think you have to ask how the doctors apply the samples and increase the concentration later. Inquiring minds...