Patient education: Porphyria cutanea tarda (The Basics)

What is porphyria? — 

This is a condition that affects how the body makes "heme." Heme is made from iron and helps blood cells carry oxygen around the body. In people with porphyria, problems making heme cause chemicals to build up in the body and cause symptoms.

There are several different kinds of porphyria:

●"Acute" porphyrias cause symptoms like belly pain and changes in brain functioning, mood, or thinking.

●"Cutaneous" porphyrias cause skin symptoms. "Porphyria cutanea tarda" ("PCT") is the most common porphyria that affects the skin. In PCT, chemicals called "porphyrins" build up in the skin.

Unlike the other kinds of porphyria, most cases of PCT are not caused by a change in a gene. PCT is usually caused by something that affects how the body handles iron. Examples are liver disease, certain infections, hormones, smoking, and alcohol use. In about 1 in 5 people, there is a change in a gene called UROD.

Sometimes, people have a change in a different gene that makes them absorb more iron. This gene is called HFE. A change in HFE causes "hereditary hemochromatosis." In this condition, the body stores too much iron.

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 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 the blisters often lead to scarring over time. Blistered skin is usually very fragile and can break or tear easily.

Sometimes, 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. You will probably first get a urine or blood test to measure the amount of porphyrins in your body. If the result is positive, you will get more tests on a sample of your blood, urine, and maybe a bowel movement.

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

●Blood tests, including tests to measure how much iron is stored in your body and to 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 you carry a change in the UROD gene, which can sometimes cause PCT. It can also check if you have a change in the HFE gene that causes the body to absorb extra iron.

How is PCT treated? — 

In people with skin blisters caused by PCT, treatment options include:

●Avoiding sun – This is most important before other treatments are used. If you need to be outside, use protection like hats, gloves, sunglasses, and sunscreen.

●"Therapeutic phlebotomy" – This means removing blood, just like with donating blood. It treats PCT by removing iron from your body. The number of treatments depends on how much iron you have. Some blood centers let you donate this blood to people who need a transfusion.

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

●Avoiding things that could increase symptoms – For example, 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 your porphyrin or iron levels are high, you can begin treatment again. Most people who follow their treatment plan do not get more symptoms, and they can live a normal life.

What if I want to have children? — 

For most people, PCT is not caused by a gene change that runs in families. But about 1 in 5 people do have a change in a 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 have children, they might choose to talk to their doctor or a genetic counselor. This can help them decide if they should be tested for the gene when they are older.

More on this topic

Patient education: Porphyrias (The Basics)
Patient education: Acute intermittent porphyria (The Basics)
Patient education: Hemochromatosis (The Basics)
Patient education: Hepatitis C (The Basics)
Patient education: HIV and AIDS (The Basics)
Patient education: Metabolic dysfunction-associated steatotic liver disease (The Basics)
Patient education: Cirrhosis (The Basics)
Patient education: Staying safe in the sun (The Basics)
Patient education: Therapeutic phlebotomy (The Basics)

Patient education: Hereditary hemochromatosis (Beyond the Basics)
Patient education: Hepatitis C (Beyond the Basics)
Patient education: Metabolic dysfunction-associated steatotic liver disease (Beyond the Basics)
Patient education: Cirrhosis (Beyond the Basics)