THURSDAY, April 11, 2013 — You may have heard of someone having peanut allergies, or being allergic to cats or dogs, but Clara's kind of allergy didn't just limit her food and pet choices — it put a serious damper on her love life.

The North Carolina woman, who asked that her name not be used, discovered she had a rare semen allergy when she married the love of her life and had sex. "I had burning and swelling and redness, which was very unusual. I thought I had contracted an STD [sexually transmitted disease],” she told ABC News. It got so bad, her husband told ABC, that "we really haven't had much sex at all for the last 10 months."

The problem turned out to be seminal plasma hypersensitivity, an allergic reaction to the proteins in her husband’s semen.

This allergy isn’t very common, in fact, only about one in every 40,000 women have it, Paula Bednarek, MD, MPH, director of the Ryan Family Planning Clinic in the Center for Women's Health at the Oregon Health and Science University in Portland told Everyday Health. Dr. Bednarek said that semen changes the pH balance in the vagina for some women, resulting in irritation, discharge, swelling, and even hives.

"This is an extremely rare type of allergy in women,” Linda Ford, MD, an allergist at the Nebraska Medical Center in Omaha and past president of the American Lung Association told Everyday Health. "In 30 years of practice, I have only seen it once.”

Interested in Sex Again

The couple said that not being able to have sex took a toll on their relationship. They started feeling “isolated, like total weirdoes” and when they stopped being intimate with each other, they felt more like roommates than husband and wife, they told ABC.

The best treatment for the condition is to wear a condom, according to Columbia University's Web site. But Clara experienced allergic symptoms even when her husband used a condom.

Another way to treat semen allergies is to isolate the proteins in the man and do skin testing on the woman to determine which ones are causing the reaction, according to ABC News. Then, the woman can be desensitized to the problematic protein.

Clara went through the desensitization process, according to ABC, undergoing a method called an intravaginal “graded challenge” in which her husband’s semen was diluted to very low concentrations and injected into her vagina.

The couple was then told to have sex within 12 hours. Clara found many of her symptoms subsided and that she felt much less pain, though she reported a small amount of swelling.

Once a woman is desensitized, she must continue to have unprotected intercourse every two to three days to remain desensitized, according to Columbia University’s Web site. This procedure can be expensive and isn’t offered in many centers. It can take many weeks to become desensitized, but it can help people who suffer from semen allergies even while using a condom.