Some women experience a range of unusual reactions around their genitals shortly after sexual contact. Some of them are sexually active for the first time, and some have been married for many years. Not long after sex, the vagina or perineum becomes edematous, itchy, and sometimes accompanied by palpitations, or even nausea and vomiting. Usually women think if they have vaginitis, and some even suspect that they have the dreaded STD. All these speculations are wrong, because this is a sign of “semen allergy”. What is “semen allergy”? What causes “semen allergy” in women? It is the presence of a substance called semen immunosuppressive substance (SIS) in male semen, which is a polymeric glycoprotein that adheres to the neck of the sperm. Its main job is to reduce the “sensitivity” of the immune system. In vitro experiments have shown that semen immunosuppressive substances have an inhibitory effect on the immune system (e.g. T-lymphocytes, B-lymphocytes, monocytes-macrophages). In vivo experiments have demonstrated that semen immunosuppressants also inhibit the cellular immune response. What exactly is the role of semen immunosuppressants? Simply put, it tells the immune system not to mistakenly injure sperm. The important function is to deantigenize sperm that have become antigens. As a result, men do not produce antibodies of their own and can avoid autoimmune reactions, which would have been clicked off by the immune system in men without the semen immunosuppressant. In addition, the substance also inhibits the female body’s rejection reaction, protecting the sperm and the fertilized egg from maternal rejection and ensuring smooth fertilization. If the semen lacks the semen immunosuppressive substance, it may cause an allergic reaction in women. If a woman is allergic, semen entering the vagina may also produce antigenic effects and cause allergy in women. Symptoms of semen allergy According to foreign studies, more than 12% of women have experienced semen allergy. Semen allergy is usually an acute reaction and its symptoms mostly peak 15-30 minutes after semen is ejaculated into the vagina, but there are also cases where symptoms appear 5 minutes, 1 hour or several hours or even days later. Women with semen allergy may experience significant peripheral reactions such as generalized itching, dyspnea, palpitations, asthma, abdominal pain, vomiting, eyelid or mucous membrane edema, wind clots, and wandering arthralgia. Some women have localized reactions, such as itching of the vulva, marked increase in vaginal discharge, redness and edema of the labia majora and minora, and an urticaria-like rash. Most people with semen allergy do not have serious reactions, but there have been cases of high fever, loss of consciousness or complete circulatory collapse due to severe semen allergy symptoms, and there have been cases of death due to semen allergy. What should I do if I have a semen allergy? The main cause of semen allergy in women is the antigenic substances in male semen, which are heterogeneous proteins for the female partner. The vast majority of reactions occur during the first sexual intercourse, but some couples who have always had a harmonious sex life, but suddenly appear, may be because the female partner has developed an idiosyncratic constitution under certain special conditions, resulting in an allergy to her husband’s semen. After the occurrence of semen allergy, first of all, do not be nervous and panic, if the reaction is relatively mild, you can suspend intercourse, wash the vulva with warm water, while using a proper squatting position to let the semen out, and then wash the vulva again. Oral anti-pyretic drugs can also be taken to relieve symptoms. Those with more serious signs and symptoms should see a doctor immediately. Desensitization therapy for semen allergy The fundamental therapy for semen allergy is desensitization therapy, which means that the female partner is gradually exposed to semen and gradually develops an adaptation process to semen, so that she will not be allergic to semen later on. The specific method is that the female partner takes anti-allergy medicine before sex, and during sex a small opening is made at the top of the condom to allow a small amount of semen to flow out. If the woman does not have an allergic reaction, the small opening on the condom can be expanded slowly until the woman does not wear a condom, does not take anti-allergy medication, and the woman does not have an allergic reaction. During the desensitization period, the female partner should use contraception to avoid pregnancy. Warm tip: Patients with semen allergy, according to the medical history and personal and family history of allergies, combined with the symptoms, the diagnosis is not difficult, but people are reluctant to consult due to traditional concepts, and even couples suspect each other whether they have a “dirty disease”, prone to omission or misdiagnosis. Therefore, patients should not be afraid to seek medical advice, but must seek timely medical consultation.