Patient education: Erythropoietic protoporphyria and X-linked protoporphyria (The Basics)

What is porphyria? — Porphyria is a condition that affects how the body makes a substance called "heme." Heme is made from iron and helps blood cells carry oxygen around the body. In people with porphyria, chemicals can build up in the body and cause symptoms.

There are several different kinds of porphyria. "Cutaneous" porphyrias cause skin symptoms. "Acute" porphyrias cause symptoms like belly pain and changes in brain functioning, mood, or thinking.

Erythropoietic protoporphyria ("EPP") and X-linked protoporphyria ("XLP") are cutaneous porphyrias. In EPP and XLP, a natural chemical called "protoporphyrin" builds up in the blood. Protoporphyrin is a normal building block for heme.

EPP and XLP are caused by genes that run in families.

EPP is the most common porphyria in children. Rarely, it shows up for the first time in adults. XLP is less common.

What are the symptoms of EPP and XLP? — The main symptom is a painful skin reaction that happens right after being in sunlight, usually within minutes. This usually starts with pain that can feel like burning, stinging, or tingling. The skin might look red, like with a sunburn, and there is often swelling.

Sunlight passing through a window or car windshield can also cause a skin reaction in people with EPP or XLP. It's even possible to have a reaction to strong indoor lights, like fluorescent light bulbs or the lights in an operating room.

The skin reaction in EPP and XLP usually lasts a day or 2 and then goes away without serious scarring. Many people find that their symptoms improve when they avoid sunlight and during the winter months, when they spend less time outdoors.

Sometimes, EPP and XLP can lead to other problems, too. But these are less common. They include:

●Gallstones – These are small stones that form inside the gallbladder, a small organ under the liver. They can cause belly pain, nausea, and vomiting.

●Liver disease – Although it is very rare, some people with EPP or XLP develop liver disease. This can cause pain, often in the upper right area of the belly. It can also cause nausea, vomiting, and jaundice (a condition that turns skin and eyes yellow).

●Low iron levels – Some people with EPP or XLP have too little iron in their blood. This can cause something called "anemia," which is when you have too few red blood cells. Anemia can make you feel tired or weak.

●Low vitamin D levels – People get vitamin D from certain foods and drinks, but also from the sun. Many people with EPP or XLP avoid sunlight, so they don't get as much vitamin D as they should.

Will I need tests? — Yes. If you might have EPP or XLP, your doctor will order a blood test that measures the amount of protoporphyrin in your red blood cells. It's important that this test be done in a lab that understands porphyria testing. If the test is positive, you will get more blood tests, too.

Some people might have other tests before finding out that they have EPP or XLP. That's because many different conditions can cause the skin to react to sunlight.

If your doctor confirms that you have EPP or XLP, you might have genetic testing. This will show whether you have EPP or XLP. Some people find out that they have the gene when they get tested after a relative is diagnosed with EPP or XLP.

If you have EPP or XLP, you will need monitoring throughout your life. You will get regular blood tests to check your protoporphyrin, iron, and vitamin D levels, as well as tests to check how your liver is working.

How are EPP and XLP treated? — Treatment mainly involves protecting yourself (or your child) from the sun and other strong lights to reduce symptoms. To do this, you can:

●Wear hats and long sleeves whenever you are outdoors, and use special sunscreen that completely blocks the sun's rays.

●Get special tinted glass for your house and car windows.

●Avoid bright lights indoors if they cause skin symptoms.

●If you need surgery, let your surgeon and anesthesiologist know that you have EPP or XLP. That way, they can protect you from lights in the operating room.

If you have severe skin pain, cold compresses can help. You might also need stronger pain medicines until the pain resolves.

Adults with EPP or XLP can take a medicine called afamelanotide, which is given as a shot under the skin once every other month. It makes your skin darker and better able to tolerate sunlight. This means that you might be able spend more time outdoors, or around strong lights, before you start having skin symptoms and pain.

If you cannot get afamelanotide, your doctor might try a medicine called beta-carotene. It is available as pills that you can buy without a prescription. Beta-carotene might help to increase your skin's tolerance for light, but it does not work as well as afamelanotide.

Depending on your vitamin D and iron levels, your doctor might suggest that you take vitamin D and/or iron supplements. It's important to get enough vitamin D to keep your bones strong.

It's also important to get vaccines to prevent hepatitis A and B. This will help protect your liver.

There are certain things that you will need to avoid, too. For example, you should not drink a lot of alcohol. You should also avoid certain medicines that can increase your risk of liver problems.

What if I want to have children? — People with EPP or XLP can have children. Some people even notice that their skin seems less sensitive to light while they are pregnant.

A porphyria expert or genetic counselor can help you understand the chance of your child developing EPP or XLP or being a "carrier" of 1 of the genes. A carrier might not get the disease, but could pass the gene on to their children.

More on this topic

Patient education: Porphyrias (The Basics)
Patient education: Porphyria cutanea tarda (The Basics)