Jeff and Clara, whose name is changed to maintain her privacy, knew every marriage has its own unique set of challenges, but theirs seemed, well, especially unique.

The first time the couple had sex - a moment they had saved for after the wedding - Clara underwent a "bizarre reaction." 

"I had burning and swelling and redness, which was very unusual," she told ABC News. "I thought I had contracted an STD."

Together the couple sought out help from doctors and took to the Internet to research what was causing the reaction. The answer, they discovered, was seminal plasma hypersensitivity, or, in other words, Clara was allergic to protein in her husband's semen. And despite efforts to alleviate the pain, such as using condoms, it persisted.

"It was a real problem," Jeff told the news outlet, "because everything else was great. We were madly in love, but this was a real game-changer for a while. It pretty much dramatically reduced our libido."

The couple said they went nearly 10 months without sex before they finally determined that enough was enough - they had to get help, no matter how much it would cost them.

They met with Dr. Jonathan Bernstein, a professor at the University of Cincinnati who specializes in allergies and immunology. In regard to allergies like Clara's, he said they're "more common ... than people realize."

In all, he estimates 20,000 to 40,000 women living in the United States suffer from the condition, though many may misjudge their symptoms as being caused by a yeast or vaginal infection or, as in Clara's case, an STD.

In order to treat the couple, Bernstein worked to isolate the proteins in order to identify the ones that were to blame and then help Clara become desensitized to the allergen through an intravaginal "graded challenge" in which she was exposed to different dilutions of the semen.

The couple were then told to have sex within 12 hours. Upon doing so, Clara said her symptoms "resolved substantially."

"Now," she said, "I am interested in having sex again." Interested enough, even, to do something she hadn't since their first day of marriage - initiate sex.

"This has been a very hopeful experience for us," Jeff said. "On a number of levels, it's been restorative. A whole side of our relationship really suffered. Now it's a whole new world."