Typically, an allergic response is not triggered the first time the body encounters the semen allergen (protein in the semen that causes an allergic reaction). In fact, some people can be repeatedly exposed to the allergen before an allergy develops. The first time or several times after the body is exposed to the allergen, the immune system becomes sensitized. During this process, the body's white blood cells develop immunoglobulin E (IgE) antibodies to the semen allergens.
Once sensitized, the antibodies quickly detect and bind to the semen allergens the next time they enter the body. These antibodies also trigger the release of chemicals, including histamine, which cause allergic symptoms such as hives, inflammation, and itchy skin, as well as anaphylaxis. Anaphylaxis is a severe allergic reaction that affects many body parts. Symptoms of anaphylaxis include low blood pressure, difficultly breathing, shock, and loss of consciousness. Symptoms can vary from mild to severe and may be life threatening without immediate treatment.
Patients who are allergic to a partner's semen are generally allergic to semen in general. Therefore, patients may experience an allergic reaction with other partners.
Women develop the reaction when they come into contact with a male's semen. This can occur during oral, vaginal, or anal sex.
Males may also develop semen allergies. It is possible for males to experience an allergic reaction after oral or anal sex with another male.
Heterosexual males may also develop also develop an allergic reaction to their own semen. This typically occurs after their blood has come into contact with their own semen. This can happen during a vasectomy (surgical procedure used to make a man sterile), testicular torsion (when a testicle twists inside the scrotum), or after an infection or trauma.
General: Symptoms of semen allergy vary among sensitive patients. The most common symptoms include burning, itching, and swelling of the genitals or areas of the skin that come into contact with the semen.
Hives: Moderate allergic reactions may cause hives. Hives are red, itchy swollen welts on the skin that may appear suddenly and disappear quickly. They often develop in clusters, with new clusters appearing as other areas clear up.
Angioedema: Some allergic patients may develop angioedema. This condition causes swelling in the tissue just below the skin. Angioedema is similar to hives, except it occurs deeper in the skin. The swellings, known as welts, usually appear around the eyes and mouth. They may also be present on the hands, feet, and throat.
Anaphylaxis (anaphylactic shock): In rare cases, a severe allergy reaction called anaphylaxis may occur. Anaphylaxis is a systemic allergic reaction, which means that many parts of the body are affected. Symptoms of anaphylaxis can vary from mild to severe and may be potentially life threatening. The most dangerous symptoms of anaphylaxis are low blood pressure, difficulty breathing, shock, and loss of consciousness, all of which can be fatal. The time lapse between ingestion/or contact with the allergen and anaphylactic symptoms varies among individuals. Symptoms may appear immediately or may be delayed from 30 minutes to one hour after exposure. Symptoms may also disappear and then recur hours later. Once symptoms arise, they progress quickly. Patients who develop symptoms of anaphylaxis should seek immediate medical treatment.
General: If semen allergy is suspected, patients may undergo either a skin test or allergen-specific immunoglobulin (IgE) test to confirm a diagnosis.
Patients who experience symptoms of anaphylaxis should be treated with epinephrine immediately. Because anaphylaxis is life threatening, a diagnosis is not needed to begin urgent medical treatment with epinephrine.
Skin (scratch) test: A skin test is used to determine whether a patient is allergic to the proteins in semen (allergens). During the test, the skin is exposed to the semen allergens and observed for an allergic reaction. If the semen triggers an allergic reaction, the patient will develop reddening, swelling or a raised, itchy red wheal (bump) that looks similar to a mosquito bite. The healthcare provider will measure the size of the wheal and record the results. The larger the wheal, the more severe the allergy.
A skin test is typically conducted in a healthcare provider's office. Skin tests cause minimal, if any, discomfort. The needles used barely penetrate the skin's surface and will not cause bleeding.
Allergen-specific immunoglobulin (IgE) test: An allergen-specific immunoglobulin E (IgE) test, commonly referred to as radioallergosorbent test (RAST®), may also be used to determine whether the patient is allergic to semen. However, this test is less accurate than a skin test. It is usually performed in patients who have coexisting severe skin diseases (like eczema or psoriasis) that make it difficult to interpret a skin test.
During the procedure, a sample of blood is taken from the patient. The blood is then sent to a laboratory that performs specific IgE blood tests. The semen allergen is bound to an paper disc called an allergosorbent. Then the patient's blood is added. If the blood contains immunoglobulin antibodies that identify and bind to the semen, the blood will bind to the allergen on the disc. A radio labeled ANTI-IgE antibody is then added to the disc to measure the level of immunoglobulin E present in the blood. The higher the radioactivity, the higher the level of IgE in the blood and the more severe the allergy.
A qualified healthcare provider will interpret the results of the test. In general, the sensitivity of these tests range from 50-90%, with the average being about 70-75%. The patient will receive test results in about seven to 14 days.
It may be difficult for patients who are allergic to semen to have children. This is because the white blood cells attack the sperm when it enters the body, significantly reducing the chance it will make it to the female's egg. However, patients can overcome this obstacle by undergoing desensitization procedures and/or artificial insemination.