Up to 12 percent of women could be allergic to semen, and many who are allergic may blame their symptoms on sexually transmitted disease instead, according to a Michael Carroll, a professor of reproductive science at Manchester Metropolitan University, who recently published a study in the journal Human Fertility.

Carroll and his colleagues conducted an unpublished survey which suggests that 12 in 100 women could be allergic to semen, according to the Daily Mail. It was unclear whether the allergy could also be present in men.

While few people have been diagnosed with hypersensitivity to human semen (HHS), the condition presents the worst effects in women between 20 and 30 years old who may show symptoms of irritation, itching, painful urination and eczema. But in the most severe instances, HHS can lead to a potentially fatal allergic reaction, the Daily Mail reports.

Because the symptoms are so similar to those of other skin conditions or some STDs, cases of HHS are misdiagnosed, Carroll wrote in previous research.

Carroll and his colleagues reportedly diagnosed four women with the condition based on their medical history and allergy tests. To make the diagnosis, Carroll separated sperm cells from the seminal fluid and tested the isolated components on women, some of whom had a reaction to the seminal fluid, but not to the sperm alone. The find demonstrated that the allergy was caused by a component in the seminal fluid - likely a glycoprotein from the prostate - rather than the actual sperm cells, the Daily Mail reported.

In April 2012, a North Carolina couple identified as Clara and Jeff told ABC News about their struggle to have sex and start a family because of HHS. They declined to use their surnames for privacy reasons.

"I had this bizarre reaction," said Clara, "I had burning and swelling and redness, which was very unusual. I thought I had contracted an STD."

"It's really bizarre," said Jeff. "Neither of us had ever come across anything like that. It was a real problem, because everything else was great. We were madly in love, but it was a real game-changer for a while."

Unfortunately for women with HHS, the find also means that someone who is allergic to one person's semen will be allergic to all semen - changing partners will not allow them to avoid the allergy. Avoiding contact with semen, either by using a condom or abstaining from sexual activity was reported as a successful way to avoid a reaction.

But HHS will pose difficulty to those wanting to start a family.

"In addition to the reaction and physical discomfort, women with HHS experience emotional stress due to the impact it can have on their relationships and the concerns about family planning," Carroll wrote, according to the Daily Mail.

"There are numerous cases published of successful pregnancies achieved naturally and through assisted reproductive technology in women with this condition. We were able to reassure our patients that HHS does not cause infertility."

In the ABC report, Dr. Andrew Goldstein, director of the Centers for Vulvovaginal Disorders in Washington, D.C. and New York City, said the condition is so uncommon, he had only treated "about a dozen" cases in the past decade.

The Daily Mail said Dr. Carroll believes the medical community's lack of recognizing HHS may be because of a lack of diagnosis along with patients not presenting their symptoms to doctors.