The symptoms can last for a whole seven days. A case report published by urologists has detailed the case of a man who developed an allergy to his own orgasms. Yes, that's right, you can become allergic to your own orgasms. A healthy 27-year-old man presented himself to the urology department at the Oakland University William Beaumont School of Medicine with an unusual complaint. For the last nine years, following ejaculation, he would develop flu-like symptoms, including coughing, swollen lymph nodes, a hive-like reaction on his forearms, and sneezing. It started when he was 18, his doctors write in Urology Case Reports, shortly after coming down with suspected epididymitis – painful swelling of the tubes in the testicles. The symptoms occurred regardless of whether orgasm occurred after sex or masturbation, and it was having a serious impact on his life. "Because of the distressing nature of his symptoms," his doctors wrote in the case report, "he actively avoided any sexual activity or romantic relationships". The team diagnosed him with post orgasmic illness syndrome (POIS). He had been seen by a variety of medical professionals, but due to unfamiliarity with the condition – there are fewer than 60 cases in the medical literature – it was something that they missed. People with POIS – females have reported the same symptoms as males, albeit rarely – can experience flu-like symptoms for up to seven days after orgasm. Other symptoms not experienced by this patient include fatigue, memory problems, headaches, mood changes, and concentration problems. There are a range of treatments available that may be useful for treating the condition, the doctors write, such as desensitization ("injecting patients with diluted autologous semen, progressively increasing the concentration based on clinical response") and hormone therapy. However, these have not been put through placebo-controlled trials. Instead, the team opted to treat the patient with an over-the-counter antihistamine, "which led to a patient-reported 90 percent decrease in his post-ejaculatory symptoms, including the rash and [swollen lymph nodes], and this has allowed him to resume sexual activity". A happy ending. Source