A man was left dreading his own orgasms after developing a bizarre "allergic" reaction to ejaculation.
The 25-year-old, who hasn't been identified, told docs he dreaded climaxing because he would suffer flu-like symptoms including anxiety, brain fog and fatigue afterwards.
His symptoms, which started as a teenager, were so debilitating he would avoid masturbation and tried not to ejaculate during s3x.
Medics from Men's Health Boston in Massachusetts explained the bizarre case in a recent article published in Urology Case Reports.
They said that his symptoms could be immediate, or delayed by two or three days, and would last between one and two weeks.
Dr Jose Bolanos, who treated the man, said: "Symptoms began at 16 years with sexual maturity and continued to the present time, regardless of whether ejaculation occurred via masturbation or intercourse with a female partner."
"For these reasons he avoided masturbation, and also attempted to avoid ejaculation when engaging in s3x with a partner.
"At the time of presentation he was single and orgasm frequency was once every two to three months."
He added that the patient's symptoms had affected his work and studies.
The man had seen several doctors and researched his symptoms extensively online.
He had also attempted various diets, supplements and allergy tablets without any sort of benefit, the medics noted.
Following extensive tests, his symptoms were diagnosed as post-orgasm illness syndrome (POIS).
The rare disorder is believed to be caused by men having an allergy to their own semen.