Patient education: Porphyria cutanea tarda (The Basics)

What are porphyrias? — Porphyrias are a group of disorders that affect how the body makes a substance called "heme." Heme is made from iron and is used in blood cells to help them carry oxygen around the body. Heme has other important roles in the body, too. In people with porphyria, chemicals called "porphyrins" can build up in the body and cause symptoms.

There are several different kinds of porphyria. Some cause skin symptoms and some cause symptoms like belly pain and changes in brain functioning, mood, or thinking. Porphyria cutanea tarda, or "PCT," is the most common porphyria that affects the skin. In PCT, porphyrins build up in the skin.

Unlike the other kinds of porphyria, most cases of PCT are not caused by an abnormal gene that runs in families. In most people, PCT is caused by something that affects how the body handles iron. Examples are liver disease, certain infections, hormones, smoking, and alcohol use. Sometimes people have an abnormal gene that makes them absorb more iron. This gene is called HFE and the condition it causes is called "hereditary hemochromatosis."

What are the symptoms of PCT? — The main symptom is blistering of the skin when it is exposed to sunlight. The blisters usually form a little while after exposure, so it's not always obvious that sun was the cause. The blisters most commonly form on areas that get a lot of sun, like the face, neck, ears, backs of the hands, and feet. The skin might be painful or itchy, and blisters often lead to scarring over time. Blistered skin is usually very fragile and can break or tear easily.

Sometimes, the hair falls out where the blisters form. Sometimes, people with PCT grow extra hair on other parts of the body, especially the cheeks or forearms.

Will I need tests? — Yes. The first test is usually a test that measures the amount of porphyrins in your body. It can be done on either blood or urine. If this test is positive, you will get more tests of your blood, urine, and possibly a sample of bowel movement.

Once your doctor has confirmed PCT, they will likely order other tests, too. These include:

●Blood tests, including tests to measure iron level and check for liver disease

●Tests to check for infection – Certain infections, including hepatitis C and HIV infection, seem to increase a person's risk of PCT.

●Genetic testing – This can show if your PCT is the result of an abnormal gene. It can also check if you have an abnormality in the gene that controls how your body absorbs iron.

How is PCT treated? — In people with skin blisters caused by PCT, treatment options include:

●Having blood removed – Doctors call this "phlebotomy." It's a lot like donating blood, except you do it regularly in the beginning, until enough iron is removed from your body. This usually takes at least few months, but is different for each person. After that you might only need it once in a while.

●Medicine – Some people get a medicine called hydroxychloroquine (brand name: Plaquenil) or chloroquine. It comes as a pill that you take twice a week, usually for at least a few months. It is generally less expensive than the treatments to have blood removed. It is not usually used in people with liver damage. Also, if you take this medicine, you will need to get an eye exam before and after treatment. That's because in rare cases it can lead to vision problems. These medicines can also cause abnormal heart rhythms in some people.

The best treatment for you will depend on several things, including your preferences about cost and convenience. Your doctor can help you decide which treatment to have. Both options work very well to reverse symptoms and help get your porphyrin levels back to normal.

Treating PCT also involves:

●Staying out of the sun until your porphyrin levels are back to normal – If you do need to be outside, use protection like hats, gloves, sunglasses, and sunscreen.

●Avoiding things that could increase symptoms – For example, you should avoid alcohol, smoking, iron supplements, and medicines containing the hormone estrogen. If you have hepatitis C or HIV, your doctor will talk to you about treating that, too.

After getting treatment for PCT, you will continue to see your doctor for tests, probably 1 or 2 times a year. If tests show that your porphyrin levels are high, you can begin treatment again. But for most people who follow their treatment plan, symptoms do not return, and they can live a normal life.

What if I want to have children? — For most people, PCT is not caused by a gene that runs in families. But about 1 in 5 people do have an abnormal gene that could be passed on to a child. If this happens, it increases the child's chance of having PCT when they get older. If you want to have children, talk to your doctor or a genetic counselor to find out if you should be tested for the gene or what your results showed.

If you have the abnormal gene and you do have children, they can choose whether to be tested when they are older. That's because PCT usually doesn't show up until adulthood.

More on this topic

Patient education: Porphyrias (The Basics)
Patient education: Hepatitis C (The Basics)
Patient education: HIV/AIDS (The Basics)
Patient education: Nonalcoholic fatty liver disease (The Basics)
Patient education: Cirrhosis (The Basics)
Patient education: Hemochromatosis (The Basics)