A woman nearly died after swallowing her lover’s semen while giving him a blow job.

The 31-year-old woman, a Spaniard, is allergic to penicillin. Unknown to her, her partner was on an amoxicillin-clavulanic acid – a form of penicillin – medication for an ear infection and the penicillin had somehow found its way down to the semen.

When she swallowed the semen, it triggered severe anaphylactic shock that doctors claim was potentially life-threatening.

The unidentified 31-year-old was rushed to hospital after she started vomiting, breaking out in hives and struggling to breathe.

The patient, from Alicante, Spain, was admitted with suspected anaphylactic shock.

She told medics that she had a penicillin allergy but denied having taken the drug before giving oral sex.

They then discovered that her partner had been on a course of amoxicillin-clavulanic acid – a form of penicillin – to treat an ear infection.

And that, according to doctors at Hospital General Universitari d’Alacant, had worked its way down into the bloke’s semen and made its way…into the patient’s mouth.

Susana Almenara, lead author of the report – published in the British Medical Journal Case Reports, is now urging anyone with known drug allergies to be aware of the potential risk and ensure they use condoms.

“We think that as clinicians, it is important to be aware of this phenomenon so as to inform and prevent potentially serious reactions in sensitised patients.

“We also recommend condom use during treatment with drugs that can induce hypersensitivity responses in partners.”

Almenara said that this was the first reported case of amoxicillin-induced anaphylaxis happening in a woman after having sexual contact with a man taking the drug.

“To our knowledge, this is the first case reported of a suspicion of amoxicillin-induced anaphylaxis in a woman after a sexual contact with a man who was taking the drug, we hypothesised an oral drug transfer through semen.”

Saying that, however, she also revealed that there had been a “few reports” of allergic reactions related to drugs being transferred through sexual intercourse.

Reactions to the drug have happened via kissing before, but this is thought to be the first through oral sex.

The bloke is thought to have taken the drug in question four hours before having sexual contact with the women.

She was given a dose of adrenalin and steroids to combat her reaction and she was breathing normally within six hours.

After a week, she had recovered entirely.

She didn’t attend the follow-up appointment she was given.

Although it is possible to be allergic to the proteins in semen, medics thought it unlikely in this woman’s case as she’s performed oral sex before without having any difficulty.

Almenara said that one in 250 penicillin treatments resulted in an anaphylactic shock.

She wants more people to be aware of how even trace elements in semen can cause issues.

“There are few cases reported of hypersensitivity reactions induced by drugs transported in semen but we have found some concern in sensitive patients about the possibility of transference of allergens via sexual intercourse.

“As clinicians, we consider that it is important to be aware of the existence of this possibility both in the diagnosis and in the prevention of anaphylactic reactions.”