- The condition is named after the Greek god of Fertility, Priapus, who was particularly well-endowed.
- Priapism is diagnosed when an erection lasts more than four hours, in the absence of any sexual stimulation.
- It is most often the result of penile injections used to treat impotence, or one of the symptoms of sickle-cell anaemia.
- Certain psychiatric medications as well as certain illicit drugs can cause priapism.
- Spontaneous prolonged nocturnal erections are a very annoying syndrome and might lead to priapism.
- Treatment must be sought urgently, as permanent damage may be done to the penis with prolonged erections.
Priapism is a very serious and painful condition, which causes a prolonged and painful erection that can last from a few hours to a couple of days. When an erection lasts for more than four hours, in the absence of any sexual stimulation, the diagnosis of priapism is made. The prolonged erection is caused by blood flowing into the penis, but not draining from it, as it normally would. The erection does not subside after ejaculation.
There are two types of priapism, called low-flow and high-flow priapism. High-flow priapism is relatively rare. In high-flow priapism there is a continuous high flow of oxygen rich blood through the penis. High-flow priapism does not cause long-term damage to the penis. In low-flow priapism the drainage of blood from the penis is impaired. The glans (head) of the penis typically remains soft and uninvolved by the process, while the shaft of the penis is filled with blood that is starved of oxygen. Prolonged low-flow priapism leads to scarring and fibrosis of the erectile tissue and permanent erectile dysfunction.
Most cases of priapism are either idiopathic (unknown cause) or related to penile injection therapy used for the treatment of erectile dysfunction. The rest are associated with drugs or diseases such as sickle cell disease, leukaemia, pelvic tumours, pelvic infections, penile trauma or spinal cord trauma. Sickle cell disease is almost non-existent in South Africa, except in black people of West African or West Indian descent, where the incidence of sickle cell disease is as high as 10%.
Who gets priapism?
This condition can occur in all age groups.
Sometimes men who suffer from impotence stimulate an erection by means of penile injection therapy. This is by far the most common cause that is seen by urologists. Some normal men will use injections for longer erections which might cause permanent damage to their erectile tissue.
Occasionally those who suffer from priapism have leukaemia or sickle-cell anaemia.
Men taking certain anti-psychotic medications can also suffer from priapism.
Signs and symptoms of priapism
A painful erection that lasts more than four hours in the absence of any sexual stimulation, is the most prominent symptom of priapism.
How is priapism diagnosed?
The length of time the erection has been present is usually a good indication to medical staff of the diagnosis.
After a doctor has carefully questioned a patient about his medical history and any medication or illicit drugs he may have been taking, physical examinations and blood tests are done. Blood count will exclude serious blood diseases. Blood can also be drawn from the penis.
The role of a blood gas sample taken from the penis is to differentiate between low-flow and high-flow priapism and can give an indication of the duration of the problem. The blood gas analysis cannot differentiate between different causes of low-flow priapism or predict the eventual outcome in any individual case.
Medication: In the early stages oral vasoconstrictions (medication that constrict blood vessels) e.g. ephedrine (Sudafed) might reverse the condition.
Irrigation: If it still doesn’t work, irrigation of the corpora cavernosa with a thick needle and saline mixed with a vasoconstrictor (pseudo ephedrine or adrenaline) is done. Irrigation is done until all the old blood is cleaved from the penis.
Bypass procedure: In cases where it still fills up with blood, a bypass procedure (shunt) is done. The sponge tissue around the urethra is not affected by priapism and a shunt between the corpora cavernosa and spongiosum is made. The shaft cylinders are opened into the sponge tissue in the head of the penis or near the base.
Outcome of priapism
Priapism can scar the penis if left untreated for more than a few hours. If the priapism does not respond to treatment quickly, chances are that a man may not regain sexual function.
When to see a doctor
Any erection which lasts for more than four hours in the absence of any sexual stimulation needs to be treated medically. This should not be postponed, as permanent damage can be done to the penis.
Reviewed by Dr Frans van Wijk, Private Urologist in Pretoria, July 2010.