Believe it or not, there are people who are allergic to sex — kind of. This rare allergy is actually an allergy to a man’s seminal fluid, a condition known as human seminal plasma hypersensitivity. Symptoms include burning sensations, rashes and welts, which is why the allergy can often be misdiagnosed as a sexually transmitted disease. The only real signifier of a semen allergy is that that symptoms appear within minutes of contact.

 

Between 20,000 to 40,000 U.S. women may experience human seminal plasma hypersensitivity, according to Dr. Jonathan Bernstein of the University of Cincinnati, but the cause of it is still being studied so it’s not clear if one person would be allergic to all men. Treatments range from always using condoms to desensitization by exposing a person to small amounts of semen and gradually increasing the amount as the body becomes accustomed to it.