A young Lithuanian woman was struggling to conceive with her partner — a rare but shocking allergy was to blame for her infertility, according to a new case report in a medical journal.
For the 29-year-old patient, four years of natural attempts and two rounds of IVF proved ineffective, stumping her doctors.
Since she’s asthmatic with a sensitivity to mold, cat fur and dust, the woman suspected that her allergies might be a contributing factor.
Subsequent blood tests revealed that she had high levels of eosinophils, a white blood cell that defends the body against allergens.
In addition to her established allergies, skin tests showed allergic sensitivity to mites, pollen, insects and dogs.
Tests also pinpointed high sensitivity to the protein Can f 5, found in dog dander and urine, which has been linked to potential sensitivities toward human semen.
The woman shared with her allergist that she frequently experienced nasal congestion and sneezing after having unprotected sex with her partner. Using samples from her partner’s semen, doctors confirmed that she has a semen allergy.
A semen allergy, also known as seminal plasma hypersensitivity (SPH), is a rare reaction to proteins found in male spermatic fluid, according to the Cleveland Clinic.
SPH is recognized as a Type 1 hypersensitivity, characterized by a rapid, exaggerated immune response to an allergen, putting semen in the same category as peanuts and pet dander.
For those afflicted, reactions to exposure to ejaculate run the gamut from burning, itching, redness and swelling of the vulva or vagina to hives, shortness of breath, dizziness and even anaphylaxis.
The primary treatment for SPH is condoms, but in this case, the woman was determined to conceive with her partner and eschewed the latex solution.
SPH does not directly cause infertility, though conception can be challenging.
Treatments for would-be parents include antihistamine medication before intercourse, anti-inflammatories after and/or desensitization therapy using diluted seminal plasma.
In cases where the allergic reaction is severe, some couples turn to using washed sperm free from seminal plasma in IVF treatments to divert the allergic trigger.
Desensitization therapy was unavailable in Lithuania, and the patient found antihistamines before sex to be “ineffective” at managing her reactions.
During a follow-up visit three years later, the woman disclosed that she was still unable to conceive and, worse still, her allergic symptoms had expanded to include eye irritation and a burning sensation in her vulva.
Her case was detailed last year in the journal Frontiers in Medicine.
SPH was initially documented in 1967, when a woman was hospitalized following a “violent allergic reaction” to sex.
For the next three decades, it was assumed that SPH affected fewer than 100 women worldwide.
Yet, a 1997 study led by allergist Jonathan Bernstein revealed that nearly 12% of reported postcoital symptoms could be classified as SPH.
The condition is now believed to affect one in 40,000 people.
The authors of the latest report said that further research is needed to understand the relationship between SPH and pregnancy. They noted that the root cause of infertility is often challenging to nail down.
“This case serves as a reminder that seemingly unrelated allergic conditions, when combined, can contribute to reproductive health challenges, warranting comprehensive evaluations,” they wrote.
