Woman suffers severe allergic reaction to partner's medication after oral sex

A woman suffered a potentially life-threatening allergic reaction to penicillin after performing oral sex on her partner, according to a case report. 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 his semen.

Susana Almenara, lead author of the report, which was 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 sensitized patients," Almenara said. "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 hypothesized an oral drug transfer through semen."

READ MORE