Even though he washed thoroughly—including his mouth and fingernails—the 20-year-old woman, who has a life-threatening allergy to a particular type of nut, suffered a severe reaction after intercourse.
“The patient’s partner was aware of the patient’s very significant nut allergy and had bathed, brushed his teeth and cleaned his nails immediately before intercourse as he had consumed mixed nuts roughly two to three hours earlier. These had included between 4 to 5 Brazil nuts,” researchers detailed in their 2007 study, published in the Journal of Investigational Allergology and Clinical Immunology.
“The patient had been diagnosed with Brazil nut allergy 2 years earlier as a result of several episodes of urticaria and angioedema after consuming foods containing nuts,” doctors stated.
The researchers continued: “The cause of the patient’s post-coital reaction was initially unclear. However, the history suggested a possible Brazil nut reaction with the Brazil nut proteins being secreted into her partner’s semen.”
If you’ve been following along, you can probably guess where this is going. No need for a biology refresher here.
Following intercourse, the woman experienced intense itching and swelling in her vaginal area and felt lightheaded even while sitting. However, she did not show clear signs of anaphylactic shock. She took an antihistamine, and within 45 minutes, her symptoms started to subside.
“Throughout the following day she noticed a marked fatigue but no skin rash, dyspnea or faintness,” researchers noted.
“The results showed an unequivocal 7mm weal to the semen sample after, but not before, he had consumed Brazil nuts (figure). The patient was asked to avoid sexual intimacy if her partner had consumed nuts and to keep antihistamines and her adrenaline pen at hand.”
“Unfortunately the couple separated soon afterwards and it was impossible to formally confirm the secretion of Brazil nut proteins into seminal fluid by Western blotting and other techniques.”
