Special Considerations

Porphyria Cutanea Tarda and Hepatitis C Virus

PCT is frequently associated with hepatitis C virus (HCV) infection. Infection with HCV is much more common than PCT, and most people with HCV do not have PCT. However, at least in some locations as many as 80 percent of individuals with PCT are infected with HCV. Therefore, HCV needs to be added to the list of factors that can activate PCT. (Others include alcohol, iron and estrogens.) It is not known how this particular hepatitis virus activates PCT. PCT is also sometimes associated with HIV infection (the virus that causes AIDS), but this is much less frequent than infection with HCV.

There are several different viruses that cause hepatitis. A blood test for HCV infection has only been available for a few years. HCV is most readily transmitted from one person to another by blood products. Although most people who are infected with HCV have a history of exposure to blood or needles contaminated with blood, in other cases it is not known how the infection was acquired. HCV (unlike the hepatitis B virus and HIV) is seldom transmitted by sexual contact. It is also not readily transmitted by casual contact with other people. Therefore, people infected with HCV are not hazardous unless they somehow expose others to their blood.

It is recommended that patients with PCT be tested for HCV infection. This is done by a blood test that detects antibodies to the virus. If HCV infection is found, it may not change the treatment of PCT (by phlebotomy or low-dose chloroquine). Treatment for PCT is highly successful even in patients with HCV. Therefore, it is reasonable to treat the PCT first and then look into treatment for HCV later. There are reasons not to treat the virus infection before treating the PCT. The only available treatment for HCV is a new drug called alpha-interferon that is expensive, requires repeated injections, commonly causes flu-like symptoms and only eradicates the virus about one third of the time. Also, liver damage progresses slowly if at all in many people with HCV. However, once the PCT is in remission it is important to assess the amount of liver damage the virus has already caused and to have follow up visits to a doctor to monitor the liver. In some cases it may be important to treat HCV infection to try and prevent progressive liver damage.

The text of this page was prepared by Karl E. Anderson, M.D. University of Texas (Medical Branch), Galveston, Texas.