Semen Allergy: The Latest Information

More than 20% of women in their 20s, 30s, and 40s experience pain during sex, but there is rarely an easy or uncomplicated answer. As a result, women are often told, “it’s all in your head.” Considering that very few healthcare providers are trained in how to deal with sexual pain, it’s important for women who are experiencing it to learn the latest research about the possible causes.

The official name for a semen allergy is “seminal plasma hypersensitivity.” Semen allergies are caused by an allergic reaction to the proteins in a partner’s semen, as opposed to his sperm. So asking a man to get a vasectomy will not help resolve a woman’s semen allergy, a fact confirmed when researchers washed sperm clean of seminal fluid and injected it under the skin of women who were allergic to semen. None of the women showed an allergic reaction to the sperm extracted from the semen, proving that sperm are not the cause of a semen allergy.

The only reported cases of semen allergy have occurred in women. There have been no known cases in which a man developed an allergy to another man’s semen. But there is a rare disorder affecting some men, called “post orgasmic illness syndrome,” that is likely caused by an allergic or autoimmune response of a man to his own semen.*

Until recently, semen allergies were thought to be very rare. However, not all healthcare providers know about semen allergies, and the diagnostic criteria for gynecological conditions such as vaginitis and dyspareunia are so broad that an allergy to semen could easily be misdiagnosed as one of these. Also, some women are too embarrassed to discuss their symptoms with a healthcare provider. So it is likely that semen allergies are not as rare as was previously thought.

Semen allergies usually come in one of two forms, localized and systemic:

LOCALIZED semen allergy occurs only in parts of the body that come in direct contact with semen. The symptoms can include vaginal pain, burning, swelling, and itching. Surprisingly, a woman who is allergic to semen will seldom have symptoms in her mouth after giving a man oral sex. However, semen that makes contact with the skin on other parts of her body can result in symptoms that occur almost immediately, especially in and around a woman’s genitals.

SYSTEMIC semen allergy occurs when a woman’s entire body experiences symptoms, such as hives, skin swelling, wheezing, chest tightness, diarrhea, dizziness, shortness of breath, and very rarely, anaphylactic shock. Symptoms can begin from minutes to an hour after exposure to semen. They usually resolve in 24 hours, although they can last longer.

The way semen allergies occur can vary. A woman could have had no problems with a partner's semen for years and then suddenly have an allergic reaction to it. But in about 41% of cases, the semen allergy happens from the first time a woman has sexual intercourse without a condom.

Current research indicates that when a woman becomes allergic to semen, she tends to have an allergy to the semen of all men. However, some women report a semen allergy to only one man and are fine with the semen of other men. Given that a man’s diet can affect the taste of his semen, it’s possible his diet could also cause his semen to be irritating. The symptoms the women experience may be due to the food or drugs their partners are consuming. Unfortunately, semen allergies are so uncommon that the research is anything but robust.

Making a Diagnosis

One of the problems in diagnosing semen allergies is that there are a number of conditions that cause similar symptoms. They include reactions to vaginal contraceptives, spermicides, and lubricants. Vulvodynia, which is pain that is felt around the vestibule or the entire vulva, can mimic some of the symptoms of a semen allergy—although some cases of vulvodynia might in fact be caused by a semen allergy. Pain that results from intercourse can appear similar to a localized semen allergy. Food and drug allergies should be ruled out as well.

A gynecologic exam should be done to check for sexually transmitted diseases, candida, and masses or other pelvic issues that could be causing pain. Both the male and female partners should be tested for herpes simplex I and II, HIV, syphilis, and hepatitis A, B, and C.

Exercise-induced asthma, which can occur during sexual intercourse, can be confused with the systemic form of a semen allergy. If a woman is experiencing asthma during sex, she should talk to a healthcare provider about getting a prescription for an inhaler that she can use fifteen minutes before having sex. If this stops her breathing problems, then it’s unlikely they are being caused by a semen allergy. On the other hand, if using a condom causes her breathing symptoms to stop, then she could very well have an allergy to her partner’s semen.

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If a woman has a thorough gynecologic exam and there are no negative findings, she would probably need to see a physician who specializes in allergies to get an accurate diagnosis. Fortunately, an even better way to diagnose a semen allergy is for a couple to use a condom to see whether its use stops the allergic reaction.

It is important for the man to put a condom on at the very start of sex play, before he produces pre-ejaculate. Nothing whatsoever that drips from his penis should make contact with any part of his partner’s body. The couple will also need to be sure there are no tiny leaks in the condom. The way to do this is to have intercourse for a couple of different nights while using a brand new condom each time.

Treatments for Semen Allergy

Fortunately, there is a treatment for semen allergy that is safe and often effective. It is called “intravaginal graded desensitization." This procedure needs to be done under the supervision of an allergist or immunologist. It is a graded challenge whereby diluted solutions of a partner’s semen are placed in a woman’s vagina every 20 minutes until she is able to tolerate undiluted semen. However, after the treatment, a couple will need to have unprotected intercourse two to three times a week in order to maintain the desensitization. If either partner travels, the man’s semen can be frozen and the woman can thaw it as needed. She can insert it into her vagina using a syringe.

If this kind of treatment is not effective, there are centers with more sophisticated equipment that can better isolate the proteins in a partner’s semen. Such procedures can help the desensitization treatment to be more effective.

Some women have reported that taking an antihistamine such as Benadryl before sex can help. Also, if a woman has a history of systemic semen allergy reactions, it’s wise for her to get a prescription for an epinephrine autoinjector. While there have been no reported deaths from a semen allergy, researchers say such a woman should error on the side of caution and have an EpiPen handy.

*There is a rare disorder called “post orgasmic illness syndrome” that impacts a small number of men. It is most likely caused by an allergic or autoimmune response that might involve his own semen combined with an opioid issue in the brain. This creates symptoms similar to drug withdrawal whenever a man with this condition has an orgasm.