Peyronie's disease is a curve in the penis.

Many men have a slight curve in the penis. As long as there is no pain or problem with sexual performance, men with a slightly curved penis should not be concerned and do not need to see a doctor.

However, some men develop a more serious bend in the penis that interferes with sexual function or causes pain. This occasionally happens after the penis is injured, either during intercourse or from a motor vehicle or industrial accident. Most cases, however, are the result of a poorly understood process known as Peyronie's disease.

In Peyronie's disease, inflammation and scar tissue form along the shaft of the penis. No one is certain why this problem occurs, but it may be triggered by repeated mild trauma during sexual intercourse. You may feel the inflammation and scar tissue as a painful lump or area of unusual firmness. In many men, the scar tissue causes the penis to bend or shorten because it prevents the penis from expanding normally. Men with Peyronie's often have difficulty achieving a firm erection, but it is unclear whether this occurs first or is caused by the scar tissue.

Peyronie's disease may occur in up to 1% of the population. Most men with the problem are between the ages of 45 and 60. The disease runs in families and appears more common in white men. In 30% of men, Peyronie's is associated with the formation of scar tissue in other parts of the body, including the palms of the hands (Dupuytren's contracture), the soles of the feet (plantar fibromatosis) and the eardrums (tympanosclerosis).

Sometimes, a serious curvature of the penis is seen in boys at or shortly after birth. This is not Peyronie's disease. Most of these cases are thought to be caused by abnormal development in the womb, and may be associated with other abnormalities of the penis such as a condition called hypospadias, in which the opening of the penis is not at the tip.

About half of men with Peyronie's disease will first notice pain during intercourse. Symptoms may appear suddenly, or may develop slowly over time. Often the penis will feel firm or lumpy at the painful site. Other men with Peyronie's will notice a painless curve of the penis that can occur suddenly or get worse over time. The penis may curve up, down or to either side. Severe changes in the shape of the penis may prevent the man from having intercourse. Men usually seek help from their doctors because of difficulty with intercourse rather than the curvature itself.

If the penis has been injured by sudden trauma, most men will be able to recall the event. Often there will be a sensation or sound of a "snap" followed by loss of erection and the appearance of a bruise. Part of the penis will remain painful for a time, but usually the area will heal over time. However, scar tissue may form and cause a new curvature. This problem is different from Peyronie's, and rarely results in difficulties with erections or shortening of the penis.

Your doctor will ask you about your symptoms and will examine your penis, looking for tender, firm areas of scar tissue (plaques) during a physical examination. Usually, this is all that is needed to diagnose the problem. If your doctor needs more information, he or she may order an X-ray to look for calcium deposits in scar tissue, or ask you to bring in photographs of your erect penis to better determine the extent of the damage. In addition, men who are considering surgery may be asked to undergo special testing of sexual function to determine the best method of repairing the problem.

A curve in the penis that is present since birth or is caused by scarring from an injury will not go away unless it is corrected with surgery.

How long Peyronie's disease lasts is difficult to predict. In more than a third of men, there is gradual improvement over 12 to 18 months without any specific treatment. In others, the scarring is permanent or worsens over time.

There is no way to prevent Peyronie's disease. However, there is some evidence to suggest that middle-aged men who engage in more vigorous or frequent intercourse are more likely to develop Peyronie's.

Most men with curvature of the penis, regardless of the cause, do not need any treatment. Men with Peyronie's disease who experience pain or difficulty with intercourse sometimes are offered medical treatment. Options include the following:

• Oral medications such as vitamin E, para-aminobenzoic acid (a B vitamin) and colchicine (sold as a generic)
• Injections of cortisone or other medications such as verapamil into the scar tissue
• Ultrasound or radiation therapy

Most of these treatments do not have serious side effects. However, none of these treatments has clearly been shown to improve the problem. Corrective surgery sometimes is offered to men with more bothersome or disfiguring symptoms. Usually, such surgery is delayed for at least a year after symptoms are stable because one-third to one-half of men with Peyronie's disease improve on their own without treatment.

In a typical procedure, the inflamed or scarred portion of tissue is removed from the penis and replaced with a graft taken from another part of the body, often the scrotum or forearm. This surgery often works well, although mild curvature of the penis may remain. In addition, sexual function or shortening of the penis may not improve following surgery. For this reason, surgeons sometimes implant a penile prosthesis at the same time that the scar tissue is removed. In some men, a prosthesis alone is enough to straighten the curvature and improve sexual function. Men who are considering surgery should be sure to discuss all the options with their physicians.

Call your doctor if:

• You notice new curvature of your penis.
• You experience pain during intercourse.
• You develop difficulties with erections.
• You notice a firm or painful lump on your penis.

One-third to one-half of men with Peyronie's disease improve without treatment. Other men have mild symptoms (such as mild curvature or decrease in erections) that can be tolerated and that do not interfere with sexual activity, so they choose not to seek treatment. Only a minority of men eventually will require surgery.

Peyronie's disease never develops into cancer or other serious conditions.