In a new meaning for ‘peanut,’ a U.K. woman has, according to this story, which really needs to be verified, become the first person to suffer an allergic reaction to nuts triggered through having sex.
The boyfriend of the 20-year-old, who has not been named, had eaten a handful of Brazil nuts just before the couple’s passion took hold.
Having recently found out she was seriously allergic to the food, she asked him to take extreme precautions.
The man brushed his teeth, rinsed his mouth out, washed his hands and scrubbed under his 
fingernails, according to science-technology website io9.
But what happened next has alerted scientists to the fact that the nut proteins can get into the seminal fluid.
After the pair had sex, the lower part of the woman’s body swelled up and she became short of breath.
Doctors at St Helier hospital in Carshalton, Surrey assumed it was a severe allergic reaction to nuts, from kissing or skin-to-skin contact.
But after the pair explained their precautions, researchers doubted that the nut proteins ended up in sweat or saliva, because the allergic reaction would have started earlier, and would have been triggered in other couples.
It is the first recorded case of an allergic reaction to Brazil nuts through intercourse.
To be absolutely certain, doctors brought the man back in and took two semen samples – one before, and one four hours after eating Brazil nuts.
They then performed a test on the girl, where they give a small injection with a needle covered in semen underneath the skin.
This is a common way to test for particular allergies.
It appears that Brazil nut proteins resist digestion, which is why they generally end up in the immune system, triggering immune reactions.
They discovered the woman’s skin swelled up and his semen caused a reaction just three to four hours after eating the nuts.
But because the couple split up after the reaction, scientists were not able to carry out further tests.
