Health condition
Erythropoietic protoporphyria
Erythropoietic protoporphyria (EPP) causes immediate burning pain in the skin on sun exposure, typically from early childhood - often invisible on examination and dismissed for decades before diagnosis.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
Which gene and test confirm it, who should be tested in the family, and which specialist to see.
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Caused by FECH gene variants (or X-linked ALAS2 forms); presents with pain, not usually blisters
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Children learn to fear sunlight; pain begins within minutes of exposure and lasts hours to days
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Diagnosis: markedly raised free protoporphyrin in red blood cells
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Management: rigorous light protection; afamelanotide implants improve tolerance; monitor liver and vitamin D
Understanding the condition
What it is and what happens next.
What causes it, how it is confirmed, and the testing and specialist routes available in the UK.
What it is and how it presents
EPP is the porphyria most likely to be disbelieved. Sun exposure - even through window glass - triggers burning, tingling agony in exposed skin within minutes, yet often leaves little for a doctor to see beyond subtle swelling, so children are labelled dramatic and adults arrive at diagnosis after an average delay of well over a decade. Protoporphyrin is excreted through the liver, and a small proportion of patients develop significant liver disease, which is why surveillance matters.
Testing, surveillance and specialist care
The diagnostic test is straightforward once considered: erythrocyte free protoporphyrin measurement, followed by FECH genetic confirmation and family counselling. Specialist services coordinate light-protection strategy, afamelanotide (approved for EPP), annual liver monitoring and vitamin D replacement for a life lived out of the sun. NHS clinical genetics services carry some of the longest waits in the health service, often many months for a first appointment, whereas private genetic testing and a specialist review can typically be arranged within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a specialist porphyria service physician. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any emergency symptoms.
Frequently asked
Common questions about Erythropoietic protoporphyria.
Quick, plain-English answers to what people ask us most.
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Can you explain what erythropoietic protoporphyria is?
Erythropoietic protoporphyria refers to a recognised clinical condition that a GP or specialist assesses using your history, examination and, if appropriate, targeted investigations. The way it presents and its impact can vary considerably from person to person.
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What causes erythropoietic protoporphyria?
Erythropoietic protoporphyria can arise from several different underlying mechanisms, and in many cases more than one factor contributes. Identifying likely causes usually forms part of the initial specialist work-up.
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What does erythropoietic protoporphyria look like?
Symptoms of erythropoietic protoporphyria vary from person to person and can range from mild and easily missed to significant enough to affect daily life. Because overlapping conditions can produce similar symptoms, a clinical assessment is the most reliable way to confirm what's actually going on.
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Can erythropoietic protoporphyria cause complications?
Most cases of erythropoietic protoporphyria are manageable with appropriate care, though, like many conditions, it can occasionally lead to complications if left unassessed or untreated. Your clinician can give you a realistic sense of the risks based on your specific presentation.
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Is erythropoietic protoporphyria hereditary?
In most cases erythropoietic protoporphyria isn't straightforwardly inherited, though family history can sometimes be a relevant background factor. A clinician can help you understand whether it's worth mentioning relatives' health when being assessed.
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Is there a cure for erythropoietic protoporphyria?
Erythropoietic protoporphyria can often be managed effectively, and in some cases prevented or reversed, with the right combination of lifestyle changes, medication or other targeted treatment. A specialist will tailor the approach to your circumstances rather than applying a one-size-fits-all plan.
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How is erythropoietic protoporphyria treated?
Treatment for erythropoietic protoporphyria is usually built around the severity of your symptoms and any underlying cause found on assessment, and may involve lifestyle measures, medication, physiotherapy or, in some cases, a procedure. Your specialist will discuss the pros and cons of each option with you before agreeing a plan.
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What's the outlook for erythropoietic protoporphyria?
The outlook for erythropoietic protoporphyria varies widely depending on the underlying cause, how early it's diagnosed, and how it responds to treatment. Many people see significant improvement with appropriate care, and your specialist can give you a more personalised timeframe once they've reviewed your case.
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Could erythropoietic protoporphyria be confused with another condition?
Because several conditions can share similar symptoms to erythropoietic protoporphyria, clinicians often consider a short list of possibilities before confirming a diagnosis. This is one of the main reasons a proper assessment, and sometimes targeted tests, matters more than relying on symptoms alone.
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When should I see a doctor about erythropoietic protoporphyria, and how quickly can I be seen privately?
It's worth seeking medical advice if symptoms of erythropoietic protoporphyria are persistent, worsening, or affecting your daily life, rather than waiting for them to resolve on their own. NHS routine referrals for this kind of assessment can take anywhere from around 20 to 45+ weeks, whereas private consultants typically offer an appointment within about two weeks.