Can You be Allergic To Someone's Semen? We Asked An Expert & Here's What They Said

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Have you noticed a burning, itching, swelling sensation in your genitals after sex? Or maybe on your hands or around your mouth? Your first thought probably goes to STIs, but if your partner has a penis, it's possible you could have a semen allergy. Yup, you read that right: It’s possible to be allergic to ejaculate. That’s the bad news. The good news is that semen allergies are incredibly rare. As in, 100 reported cases since 1958, rare. (Although new research suggests it may be more common than previously believed so, ya know, do what you will with that information.)

“It’s very rare for a woman to have an allergy to semen,” Dr. Susie Gronski, physical therapist and pelvic rehabilitation practitioner, tells Bustle. “The prevalence of the allergy is unknown and estimates are only guesses at this time. So there’s no need to instill fear in women or men regarding a semen allergy, as it is extremely rare.”

So what exactly are people with semen allergies (also known as seminal plasma hypersensitivity) allergic to, anyway? Dr. Susie says that it’s not totally clear, but the current going theory is that a person — usually a woman — is allergic to either protein fluid produced by the prostate or seminal fluid. The allergy can show up randomly, even after multiple times having sex with the same person. Or, alternatively, it could not be present with one partner, only to pop up with the next.

What Are The Symptoms?

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The symptoms of a semen allergy are, unfortunately, really similar to the symptoms of bacterial vaginosis. Or a yeast infection. Or a number of STIs. They’re also similar to other allergies, but show up on the genitals or — in the case of contact from oral sex or hand jobs — on the mouth and hands, respectively.

“Symptoms of a semen allergy are similar to any allergy that you might have,” Dr. Susie says. “Itching, burning, redness, swelling of the local vulvar tissue. Sometimes, and again very rare cases, symptoms can be systemic.”

So, possible symptoms of a semen allergy include: burning, itching, swelling, hives, and — rarely — anaphylactic shock.

Is It Possible To Be Allergic To All Semen?

Because it’s such a rare condition, the research on semen allergies is pretty thin. However, Dr. Susie says that, based on the research that does exist, an allergy to all semen would be super rare. Also? Hard to prove.

“The body’s immune system can be affected by lifestyle, stress, and even thoughts/beliefs which can trigger a sympathetic fight or flight response in our body, which impacts the nervous system, immune system, musculoskeletal system, reproductive system and so forth,” Dr. Susie says. “So to say that someone is allergic to all semen would be very hard to prove in the research and very hard to isolate due to individual molecular makeup and external variables from both male and female.”

Here's What You Can Do About It

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First of all, you should get tested to see if what you’re suffering from is actually a semen allergy. The test is similar to any other allergy test — a skin prick test should do it. Some doctors might ask that you bring a sample of your partner’s semen, due to the fact that semen allergies can be a reaction to a particular person’s semen.

Once you’ve been diagnosed with a semen allergy, the best way to avoid an outbreak is to use a condom during sex. As long as you’re not getting semen to skin contact, you should be OK. Some studies have shown that people with semen allergies can build up a tolerance from repeated exposure, but that’s an experiment you should run with your doctor, not on your own.

“But my favorite way to ease allergic reactions is boost up your immune system,” Dr. Susie says. “Allergies come about because the body isn’t able to fight off change, or from an imbalance that occurs in the body. Diet and lifestyle can be a game changer.”

Final word is: If you have something unusual/painful/smelly going on in your genitals, go to the doctor. Let them run the usual tests for STIs, bacterial vaginosis, and yeast infections before you get to the semen allergy. But if you’re coming back from test after test with no conclusion, you might be one of the rare ones with this issue.