Peyronie's disease is characterized by a localized scarring of the tunica albuginea of the penis. The cause of Peyronie's disease appears to be multi-factorial and has not been fully explained. As bending of the penis occurs in all men during penetrative sexual intercourse, only a small percentage of men manifest plaque formation. While trauma is believed to be the initial event, many theories have been proposed for the pathogenesis of Peyronie's disease, including: auto-immune factors, excess production of chemicals (known as cytokines) in the tissue of the penis, and abnormalities of cell behavior. Peyronie's disease appears to be more common in certain ethnic groups, particularly northern European Caucasians; it is uncommon in African-American men and rare in Asian men.
Risks of Peyronie's Disease include advanced age, diabetes, and erectile dysfunction. It is also believed that there is an association between Peyronie's disease and Dupuytren's disease (aka Dupuytren's contracture). Dupuytren's disease is a scarring (fibromatosis) of the hand leading to hand deformities. Between 10-20% of men with Peyronie's disease will also have Dupuytren's disease. Having prostate cancer surgery is also a risk factor for developing Peyronie's disease. As many as 16% of men undergoing surgery for prostate cancer may develop Peyronie's disease within 3 years of having surgery. Another possible cause of Peyronie's disease was believed to be hypogonadism, or low testosterone, although this has not held true.