While rare, human seminal plasma hypersensitivity—an allergy to semen—does exist. Talk to your doctor if you have any of these symptoms after sex.
You feel the burn
A semen allergy can show up immediately after your partner ejaculates, and you might have burning, redness, swelling, and blisters in your vagina, says Sherry A. Ross, MD, author of she-ology and expert on the MedAnswers platform. A semen allergy isn’t the only culprit with those types of symptoms though, so talk to your doctor before jumping to conclusions. Seminal plasma hypersensitivity only affects an estimated 20,000 to 40,000 women, so the doctor will need to rule out other allergies, such as reactions to condoms, spermicide, or scented tampons, plus STIs before considering a semen allergy, says Dr. Ross.
You’re getting itchy
With an itchy vagina, your first thought would probably be a yeast infection, and that is a good place to start—after all, an estimated 75 percent of women will get at least one yeast infection in her life, making it far more common than a semen allergy. But if you don’t have that telltale cottage cheese-like discharge and the itching only shows up after sex, ask your doctor about a semen allergy, suggests Peter Rizk, MD, fertility expert and obstetrician-gynecologist based in Mobile, Alabama.
This never happened before your current partner
All semen is not created equal. There’s a chance your antibodies react to one particular protein in a new partner’s semen that you’ve never been exposed to in the past, which is why you’re just feeling the symptoms now. “She could be perfectly normal with one person and perfectly uncomfortable with another,” says Dr. Rizk.Unfortunately, that’s also why it can be so tricky to diagnose. Because the reaction is specific to the proteins in your partner’s semen, you likely won’t be able to see an allergist for allergy testing, says Dr. Ross. There are treatments available though. A doctor can desensitize you to your partner’s semen either by inserting a small amount of seminal fluid into your vagina, or give you allergy shots with the semen proteins. Not every allergist will be equipped for the treatment though, so ask a urologist for recommendations, suggests Dr. Ross.
You only get symptoms with unprotected sex
If you’re allergic to latex, your symptoms would only show up if your partner is using a condom. With seminal plasma hypersensitivity, just the opposite would happen: You’d only get symptoms if a condom was not keeping semen away from your body. That doesn’t mean you need to deal with the pain if you want to have kids though. If the desensitization treatments aren’t working, a doctor can wash the semen to remove the plasma you react to, then do intrauterine insemination, says Dr. Rizk.
You’re breaking out in hives
Seminal fluid hypersensitivity might not just stay localized in the spot the semen touched. “It can create hives and swelling, similar to what would happen if you have an allergy to anything else,” says Dr. Ross.
You’re having trouble breathing
This isn’t the typical quick breathing you do when things are getting hot and heavy. “You would think something is wrong,” says Dr. Rizk. While a severe reaction is potentially life-threatening, Dr. Rizk emphasizes that he’s never heard of a deadly reaction to semen, though the symptoms might get bad enough to make you go to the ER.
Oral sex is uncomfortable, too
Pain, swelling, redness, and blistering in your mouth after oral sex could be a red flag of a semen allergy. “If your body is reacting to the same proteins from the ejaculation, you could have that same allergic reaction,” says Dr. Ross.
