Being allergic to cats is still okay, but can you be allergic to another person? For Maura, 43, this question has become vital. It all started in his twenties. “I noticed that my private parts were burning after unprotected sex”she says in a BBC article. Initially thinking it was a reaction to cosmetic products, she eventually realized that the real trigger was… contact with semen.
The symptoms, initially localized, worsened: burning, redness, then one day, his tongue swelled after intercourse. His companion becomes alarmed and administers him an inhaler at the last minute. Since then, the couple has lived under high vigilance, convinced that a faulty condom could be fatal.
Although semen allergy – or hypersensitivity to seminal fluid – is extremely rare, it is nevertheless very real: less than a hundred cases have been recorded worldwide. Symptoms vary and range from simple itching to anaphylaxis, the most serious form of allergy, which can be life-threatening. Most often, the reaction is linked to a seminal plasma protein, a substance produced by the prostate, but the exact mechanism remains poorly understood by doctors.
“It’s like acid”analyzes the Dr Jonathan Bernstein, professor of medicine at the University of Cincinnati (Ohio) and allergy specialist. The sudden onset of pain makes the situation psychologically and physically very difficult to live with.
But sexuality is not the only area where humans become a walking allergen. People with a vague condition called “People Allergic To Me” or PATM live in real hell. By their simple presence, they trigger allergic-type symptoms (cough, itching) in those around them, without us really understanding why.
In a study published in 2023 in the journal Scientific Reports, a team of Japanese researchers identified in these patients an abnormally high emission of toluene, a gas usually metabolized by the liver and released by the skin. However, the concept of PATM does not yet have official medical status.
Costly desensitization
Bodily fluids are also vectors of unexpected reactions. The medical literature is full of cases of women or men reacting intensely after a saliva exchange with partners who have consumed allergenic foods (nuts, seafood, etc.), or medications, despite careful washing. Cross allergies during kissing are well documented, as are those occurring after sexual intercourse with people under antibiotic treatment.
Semen is not the only fluid involved and similar reactions have been reported with vaginal secretions. Marek Jankowski, professor of dermatology and venerology at the Nicolaus Copernicus University in Toruń (Poland), observed redness and itching in men after intimate contact. “Many doctors don’t believe it, but our surveys show that (this allergy) affects as many people as that to sperm.” However, it would tend to decrease with repeated exposure, where allergy to seminal plasma requires real desensitization protocols.
The heavy price
How is this hypersensitivity to others treated? The Dr Bernstein details his method: separate sperm and plasma, dilute the liquid, then introduce it gradually, in increasing doses, into the patient’s vagina. This expensive protocol, rarely offered outside large medical centers, often proves effective, allowing you to have unprotected sexual intercourse without risk with the same partner.
The emotional impact of these allergies is far from negligible. Maura, for example, made the difficult choice to give up motherhood: the risks and costs linked to medical follow-up seemed insurmountable. For a couple, intimate life requires vigilance and a lot of communication: “(My partner) told me he was hurt by the idea that I was allergic to his sperm. He doesn’t blame me, just the universe.” Added to this is the view of society, which is often skeptical or mocking towards these invisible and poorly understood pathologies.
Behind these rare cases, science questions the mysteries of the human immune system. The latter, designed to defend us from intruders, can sometimes get carried away to the point of transforming our relationship with others into a biological ordeal. If allergy to others disrupts daily life, the stories of Maura and other patients remind us of the importance of diagnosis, recognition and medical and psychological support.
