Sexually Transmitted Diseases
Burning semen is a common symptom of a number of different sexually transmitted diseases (STDs). STDs are typically viral infections that pass from person to person during sexual intercourse or other intimate sexual contact. They usually have a fairly broad list of symptoms, many of which will get worse and more pronounced the longer things go untreated. These can include unusual penile discharge, blisters, redness, pain during urination, and a foul odor. Trichomonaisis is one of the most common sexually transmitted diseases which may be linked to burning semen; gonorrhea may also be to blame.
Most STDs can be treated when detected early. Treatment may include medication and abstinence from sexual intercourse. It is possible to be re-infected with most diseases in this class, which makes using protection really important for anyone who is not in a committed, monogamous relationship with a partner who is known to be disease-free.
Inflammation and Infection
A number of infections in the urethra and around the penile opening may initially look like STDs, when in fact they are caused by something else entirely. Bacterial strains that have penetrated the tissues, particularly if there is a scratch or wound, are one of the most common. Bacteria love warm and moist environments, and may settle down in the penis to multiply. This often causes a burning, stinging sensation when ejaculating — though in most cases this also happens during urination.
Yeast infections tend to be most frequently associated with women, but they can happen in men, too, particularly men who engage in intercourse with infected women. These sorts of infections are typically caused by a particular yeast strain, Candida albicans, that populates the inner walls of the vagina. Healthy women usually have a vaginal chemistry that prevents unchecked growth, but when the chemical balance falls apart, whether due to hormones, medication, or some other factor, the yeasts can grow in an out-of-control fashion. This often leads to burning, itching, and general pain, and the problem can spread into the penis during intercourse. In a man, this infection typically stays lodged in the tip of the penis, though it can spread up the urethra and throughout the reproductive system if not promptly treated.
Injury and Trauma
Men who have been in accidents or who have sustained trauma to their penis or testicles may also experience burning semen from time to time, usually as a result of the body’s natural healing process. If the pain persists, though, it may be a sign that things aren’t actually healing properly. In most cases things will correct themselves with time, and the burning here is usually just a sign that there has been an injury somewhere within the system. Abstaining from ejaculations and intercourse in the short term is usually the best way to facilitate healing.
Sometimes the burning doesn’t stop with the ejaculation, though. When the sensation happens any time semen so much as touches the skin, a plasma allergy may be to blame. This type of reaction may lead to symptoms similar to any other allergic response, including itchiness and redness. It used to be thought that men could not have an allergy to their own semen, but modern research has largely disproved this theory. A man's sexual partner may also have an allergy to his, or all, semen.
A semen protein allergy is relatively rare, although not unheard of. Treatments are usually similar to those in other cases of topical allergy, and in most cases they aim to reduce irritation and discomfort. Women who have a reaction to their partner's semen should also try to avoid contact through the use of condoms.
Most experts recommend that men get a medical evaluation any time they feel a burning sensation that either doesn’t go away on its own after a few days or seems to be getting worse with time. Certain medications can reduce the symptoms, and keeping track of what may be causing the problem can help prevent future episodes as well as rule out and treat more serious conditions as they arise.