When a 20-year-old woman in the United Kingdom rushed to the hospital with a swollen face, hives spreading across her body, and difficulty breathing, doctors knew immediately what likely happened. The symptoms seemed familiar — an allergic reaction — but the trigger was anything but ordinary.
Indeed, the woman has a severe allergy to Brazil nuts and experienced reactions in the past after ingesting them. But this time, she hadn’t eaten any nuts. Instead, she had engaged in unprotected vaginal sex with her habitual partner shortly before her symptoms began.
What made the case truly perplexing was the thorough preparation her partner had undertaken. Hours before their intimacy, he had eaten Brazil nuts. But since then, he had bathed, brushed his teeth, and cleaned under his fingernails. Despite these precautions, her body reacted as if it had been directly exposed to the allergen.
A bizarre case
The doctors delved deeper. Through a series of skin prick tests using the man’s semen, they uncovered the cause. When the sample contained traces of Brazil nut allergens, it triggered a welt on her skin, confirming their hypothesis: the allergenic proteins had been transmitted through his semen during intercourse.
“Skin prick testing with the boyfriend’s semen after Brazil nut consumption confirmed significant reactivity whereas a sample before nut consumption was negative. We believe this to be the first case of a sexually transmitted allergic reaction,” wrote doctors from St. Helier Hospital in a 2007 case report.
The peculiar case highlights how sensitive food allergies can be, even when the allergen isn’t consumed directly. Although similar cases involving intimate contact have been documented, such as reactions caused by kissing, the transmission pathway in this instance was unprecedented.
For the young woman, the outcome was fortunately manageable. After taking an oral antihistamine, her symptoms subsided within 45 minutes, Live Science reported. The next day, she felt fatigued but otherwise fine. Still, the incident prompted doctors to recommend carrying antihistamines and an adrenaline pen at all times. Abstaining from sexual contact following nut consumption by her partner was deemed vital.
While the young woman’s story ends on a positive note, it serves as a call for heightened awareness regarding allergies: sometimes, even love can carry unexpected dangers.
