For two years, a 26-year-old woman suffered burning and swelling in and near her vagina for 15 minutes after making love. But she and her husband were puzzled because the symptoms went away if they used a condom. She finally went to her doctor, and what she learned there was startling. She is allergic to sex.

In another case, a 30-year-old women went to her doctor because she was having painful burning and tingling in and around her vagina immediately after intercourse. The symptoms then lasted for about six hours. Moreover, several love-making sessions caused her face to swell. But, the woman told her doctor there were no symptoms at all when her husband used a condom.

How Can This Be?

Researchers have found that some women are allergic to their male partner's seminal fluid, the thick liquid that carries sperm. Doctors know the disorder as "human seminal plasma hypersensitivity." But there is good news. The condition can usually be treated by allergists although it takes some effort by concerned, caring male partners.

What Are the Symptoms?

Most sufferers complain of symptoms that include vaginal itching, burning, and swelling in the genital area after sex. Some women even report blisters in and near their genitalia. Wheezing, hives all over, chest tightness, vomiting, or diarrhea are other possible symptoms. Severe reactions can include loss of consciousness or complete circulatory collapse.

Both that patient and the 26-year-old woman saw an allergist. Through a skin reactivity test, they discovered they were indeed allergic to their husband's seminal fluid. Researchers have not yet identified the troublesome culprit, but they think that certain proteins in the seminal fluid cause the reaction.

How Is a Sex Allergy Treated?

Once the hypersensitivity is diagnosed, partners are called on to do more than just use a condom. Treatment involves injecting the women regularly with their partner's purified seminal proteins.

For the initial diagnostic screening, only a single sample of the male's ejaculate is needed. But then the allergist needs 5-7 days worth of ejaculate to have the volume to formulate enough vaccine for regular injections.

One of the couples went through all the trouble of having the puzzling, painful symptoms diagnosed as sexual allergy. They then worked out a treatment plan, only to discover yet another dimension of human seminal plasma hypersensitivity.

Says Dr. Jonathan Bernstein at the University of Cincinnati College of Medicine, "When we start giving the woman injections, and she and her partner stop having sex, she can lose her tolerance to his seminal plasma." In other words, couples must continue to have regular intercourse or the bothersome symptoms will return.

This created some logistic difficulties for the 26-year-old woman. Her husband was an airline pilot who was out of town frequently, so she was at a loss as to how they would continue their "treatments."

Dr. Jonathan Bernstein to the rescue. "We tell our patients that if they must be apart for some weeks, the male can leave several samples of ejaculate and the woman can then inject a small amount into the vagina. That will keeps the woman's tolerance up."