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MEDICAL MYSTERY

Woman’s deadly nut allergy flares up after unprotected sex with her partner – in ‘first case’ of its kind

Her doctor suspected that her boyfriend's semen had traces of the Brazil nut allergens triggering her allergic response
Brazil nuts in a bowl.

SEX for one couple took a dangerous turn when a young woman suffered an allergic reaction to her boyfriend's semen.

Shortly after the act had reached its natural end, the 20-year-old began experiencing intense itching and swelling in her vulva.

Two pairs of feet sticking out from under a white bedsheet.
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She also felt faint and mildly short of breath, even while sitting.

The unnamed woman quickly recognised she was having an allergic reaction, having been diagnosed with a severe Brazil nut allergy two years earlier.

She took 10 milligrams of cetirizine, an antihistamine, and her symptoms improved within 45 minutes.

Experts at the Department of Immunology at St Helier Hospital in Surrey, who treated the woman, believe this to be the first documented case of Brazil nut proteins being transmitted through semen.

Read more on allergies

Before the couple's encounter her partner had eaten four to five Brazil nuts, a few hours earlier.

But knowing about her allergy he had taken precautions, including bathing, brushing his teeth, and cleaning his nails.

The couple opted not to use a condom, as she was on the contraceptive pill.

After visiting the Surrey hospital, her doctor suspected that her partner’s semen had traces of the Brazil nut allergens triggering her allergic response.

To confirm, they performed skin prick tests using his semen.

One sample was taken before he ate nuts, and another two-and-a-half hours after.

Allergist explains the difference between allergies and anaphylaxis

The second sample caused a clear allergic reaction, confirming their theory.

"To our knowledge, this is the first case of a severe food
allergic reaction transferred by normal vaginal intercourse," the doctors wrote in the , in 2007.

There are other documented cases of individuals with severe allergies developing local allergic reactions after intimate contact.

However, the culprit is usually the direct transfer of allergens through touch or kissing.

Three Brazil nuts isolated on white background.
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"It would be interesting to see if other food proteins may be secreted into semen and present a hazard to sexually active individuals with a
significant food allergy," they added.

Doctors advised the woman to avoid intimacy if her partner had eaten nuts.

They also recommended keeping antihistamines and an adrenaline pen on hand.

The signs of an allergic reaction and anaphylaxis

SYMPTOMS of an allergy usually occur within minutes of contact with with the offending food or trigger, but they can also come on up to one hour later.

Most allergic reactions are mild but they can also be moderate or severe.

Anaphylaxis is the most severe form of allergic reaction which can be life-threatening.

Mild to moderate symptoms include:

  • Itchy mouth, tongue and throat
  • Swelling of lips, around the eyes or face
  • Red raised itchy rash (often called nettle rash, hives or urticaria)
  • Vomiting, nausea, abdominal pain and diarrhoea
  • Runny nose and sneezing

Severe symptoms of anaphylaxis include:

  • Swelling of your throat and tongue
  • Difficulty breathing or breathing very fast
  • Difficulty swallowing, tightness in your throat or a hoarse voice
  • Wheezing, coughing or noisy breathing
  • Feeling tired or confused
  • Feeling faint, dizzy or fainting
  • Skin that feels cold to the touch
  • Blue, grey or pale skin, lips or tongue – if you have brown or black skin, this may be easier to see on the palms of your hands or soles of your feet

Anaphylaxis and its symptoms should be treated as a medical emergency.

Follow these steps if you think you or someone you're with is having an anaphylactic reaction:

  1. Use an adrenaline auto-injector (such as an EpiPen) if you have one  instructions are included on the side of the injector.
  2. Call 999 for an ambulance and say that you think you're having an anaphylactic reaction.
  3. Lie down – you can raise your legs, and if you're struggling to breathe, raise your shoulders or sit up slowly (if you're pregnant, lie on your left side).
  4. If you have been stung by an insect, try to remove the sting if it's still in the skin.
  5. If your symptoms have not improved after 5 minutes, use a 2nd adrenaline auto-injector.

Do not stand or walk at any time, even if you feel better.

Sources: Allergy UK, NHS 

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