Nut allergies are no laughing matter -- you have all made that abundantly clear in comments left on previous posts. But maybe this story will give you a good snicker.
Discovery Magazine recently reported a story from a Spanish medical journal with the following keywords: Brazil nut allergy. Semen. Sexual transmission. The title is even better: Dangerous Liason: Sexually Transmitted Allergic Reaction to Brazil Nuts.
Ruminate on that title for a moment.
We have all heard food allergy horror stories. How the most fleeting contact, with the most minute quantity of allergen, can cause a sensitized person to fall into anaphylaxis. What makes this case different, prurient interests aside, is that there was no direct contact between a person with an allergy and the thing they are allergic to.
What went down: It's the classic story of boy meets girl. Boy finds out the girl has a horrific allergy to Brazil nuts but simply cannot give up eating their tasty flesh. Boy has no desire to repeat the worst parts of "My Girl" and takes measures. He brushes his teeth, cleans his nails and even takes a bath.
Despite these precautions, the woman still ended up with rashes and swelling all over her body. In what has to be one of the more awkward conversations with her doctor, they narrowed the possible causes down to one thing: Her boyfriend's semen.
A quick "skin prick" test with her partner's semen, before and after consuming a handful of nuts, revealed that the Brazil nut allergen was making its way through his body and into his semen.
How on Earth is that possible? People are not allergic to a whole nut, they are usually only allergic to a specific compound within that nut. In the case of Brazil nuts, it is a particular kind of protein that our body does not breakdown easily. We can still absorb it though and it ends up floating around inside the body and apparently, if you have the relevant hardware, into the semen. Oddly, it's only semen. Other bodily secretions like saliva and tears were tested and lacked the offending protein.
The take home lesson: Like so many other awkward conversations with a doctor, this could have been prevented with a condom.
Peanut allergies? While we certainly can't say anything definitive, our cursory research has failed to yield any other documented cases of nut tainted semen causing an allergic reaction. The authors of the original report speculate that the body has difficulty breaking down the specific protein in Brazil nuts that cause an allergic reaction. So it may very well be that this is a case specific to Brazil nuts.
The full report can be read here.