Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Erythropoietic protoporphyria(EPP) is one of several rare inherited disorders calledporphyrias. Patients with EPP have mutations in one or more genes that cause them to have decreased activity of an enzyme called protoporphyrin IX in their red blood cells. This leads to a buildup of a protein called protoporphyrin that can make their skin very sensitive to sunlight.
Patients with EPP can experience severe pain when they are in the sun or even exposed to some intense artificial lighting. These symptoms usually begin in childhood and persist throughout a patient’s life.
EPP is the third most common porphyria—estimated to occur in about one in about 74,300 individuals—and the type most often seen in children.Women and men appear to be equally affected. While there is currently no known cure for EPP, there are ways to manage it.
This article looks at the symptoms and causes of erythropoietic protoporphyria, including how the condition is treated.
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Erythropoietic Protoporphyria Symptoms
Patients may also have other skin symptoms after they’ve been exposed to sunlight, including:
Pain and other symptoms are felt most often on the face, hands, and arms. Patients often notice the symptoms happen more frequently in the summer. These symptoms can range from mild annoyances to severe and debilitating in their day-to-day lives.
Symptoms usually go away within 24 hours. Patients with EPP usually do not experience any lasting skin damage, like scarring (though blisters and scars can result from other types of porphyrias that affect the skin).
Some patients with EPP may also experience liver damage, as having too much protoporphyrin in the body can put stress on the liver. It is rare to have severe liver damage from EPP, however—this complication occurs in less than 5% of patients.Studies suggest that some patients with EPP (25% to 30%) may also experiencegallstonesthat have protoporphyrin in them, which can lead to gallbladder inflammation (cholecystitis).
What Causes Erythropoietic Protoporphyria?
The mutations in the FECH gene are passed down in a pattern calledautosomal recessive. This means that one parent has a very strong mutation and the other has a weaker one. A child receives both mutations, but the stronger mutation dominates the weaker one. The parent who has the strong mutation won’t have symptoms unless they also have a weaker mutation from one of their parents. If they don’t have symptoms, they are what’s called a “carrier." This means that even though they don’t show symptoms of the disease, they can pass the gene that causes it on to their child.
Inheriting these mutations in the FECH gene causes a patient to have too much protoporphyrin IX in their red blood cells and plasma. The protoporphyrin builds up in the bone marrow, the blood cells, and the liver.
Symptoms related to sunlight exposure typically appear in childhood—even in infancy—but it may take time to get diagnosed with EPP. Children may lack the language to express they are in pain. If they have no visible skin symptoms, it can be difficult for parents or doctors to make the connection. EPP is also a very rare condition. As a result, many pediatricians and general practitioners may not be familiar with it.
Once a doctor suspects a patient has EPP, it is very easy to test for it and confirm the diagnosis. There are several tests to detect abnormal levels of protoporphyrin in the blood, urine, and feces.
Additionally,genetic testingmay reveal the specific mutations in the FECH gene. This can be very important information for patients, as they may want to seek genetic counseling when they begin thinking about family planning.
If one family member is found to have EPP, it is not uncommon for other members of the family to be tested to see if they carry a mutation as well, even if they aren’t showing symptoms.
Erythropoietic Protoporphyria Treatment
The most important treatment for patients with EPP is sun protection. Avoiding or limiting sunlight exposure, as well as any exposure to some forms of fluorescent light, is the best way to prevent and control symptoms.
Examples of sunlight protection can include:
Patients with EPP may be advised to avoid certain medications or supplements, such as estrogen-containing birth control pills orhormone replacement therapy, testosterone supplements, or any drugs that have certain effects on the liver. For this reason, patients may also be advised not to drink alcohol.
When patients with EPP undergo surgery, there may need to be special considerations regarding anesthesia. Patients may also need extra protection during surgery to avoid symptoms after being exposed to the strong overhead lighting used in operating rooms.
Are There Medications to Treat Erythropoietic Protoporphyria?
Summary
Erythropoietic protoporphyria is a rare inherited metabolic disorder that causes severe pain when the skin is exposed to sunlight. Other skin symptoms may include itching, burning, and swelling. There is no cure for EEP, and treatment generally involves protecting the skin from sunlight.
For patients with EPP, having to avoid sunlight can have a negative impact on quality of life, especially in terms of social experiences. Resources likeCamp Discoveryprovide opportunities for children and their families. Additionally, the Guest Relations departments of Disneyland and Disney World are also able to make accommodations for families and children with EPP so they can enjoy many special childhood experiences and take part in activities outside with their peers.
3 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Porphyria Foundation.Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP).National Organization for Rare Disorders.Erythropoietic protoporphyria and X-linked protoporphyria.Levy C.Overview of liver involvement in patients with erythropoietic protoporphyria.Gastroenterol Hepatol (N Y). 2023;19(2):104-107.Additional ReadingErythropoietic Protoporphyria (EPP). European Porphyria Network.Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP). American Porphyria Foundation.Lecha M, Puy H, Deybach JC. Erythropoietic protoporphyria. Orphanet J Rare Dis. 2009;4:19. doi:10.1186/1750-1172-4-19.
3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Porphyria Foundation.Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP).National Organization for Rare Disorders.Erythropoietic protoporphyria and X-linked protoporphyria.Levy C.Overview of liver involvement in patients with erythropoietic protoporphyria.Gastroenterol Hepatol (N Y). 2023;19(2):104-107.Additional ReadingErythropoietic Protoporphyria (EPP). European Porphyria Network.Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP). American Porphyria Foundation.Lecha M, Puy H, Deybach JC. Erythropoietic protoporphyria. Orphanet J Rare Dis. 2009;4:19. doi:10.1186/1750-1172-4-19.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American Porphyria Foundation.Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP).National Organization for Rare Disorders.Erythropoietic protoporphyria and X-linked protoporphyria.Levy C.Overview of liver involvement in patients with erythropoietic protoporphyria.Gastroenterol Hepatol (N Y). 2023;19(2):104-107.
American Porphyria Foundation.Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP).
National Organization for Rare Disorders.Erythropoietic protoporphyria and X-linked protoporphyria.
Levy C.Overview of liver involvement in patients with erythropoietic protoporphyria.Gastroenterol Hepatol (N Y). 2023;19(2):104-107.
Erythropoietic Protoporphyria (EPP). European Porphyria Network.Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP). American Porphyria Foundation.Lecha M, Puy H, Deybach JC. Erythropoietic protoporphyria. Orphanet J Rare Dis. 2009;4:19. doi:10.1186/1750-1172-4-19.
Erythropoietic Protoporphyria (EPP). European Porphyria Network.
Erythropoietic Protoporphyria (EPP) and X-Linked Protoporphyria (XLP). American Porphyria Foundation.
Lecha M, Puy H, Deybach JC. Erythropoietic protoporphyria. Orphanet J Rare Dis. 2009;4:19. doi:10.1186/1750-1172-4-19.
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