Summary about Disease
Erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP) are genetic metabolic disorders resulting from a deficiency in the enzyme ferrochelatase (FECH). This deficiency leads to the accumulation of protoporphyrin in red blood cells, plasma, and tissues, primarily causing photosensitivity (painful reactions to sunlight). While often grouped together due to similar symptoms, EPP is usually inherited in an autosomal recessive manner, while XLP is X-linked. The major manifestation is acute, non-blistering photosensitivity appearing in early childhood. Chronic liver disease can occur in a minority of patients.
Symptoms
Photosensitivity: This is the hallmark symptom. Exposure to sunlight or even artificial light can cause intense pain, burning, itching, and redness of the skin. Symptoms typically begin within minutes of exposure.
Swelling: Affected areas of skin may swell.
Scarring: Repeated episodes of photosensitivity can lead to thickened, leathery skin and scarring, especially on the hands and face.
Liver problems: Some individuals develop liver disease, ranging from mild elevations in liver enzymes to severe liver failure. Gallstones are also possible.
Anemia: Mild anemia may occur.
Causes
The underlying cause is a deficiency in the enzyme ferrochelatase (FECH). This enzyme is responsible for inserting iron into protoporphyrin to form heme, a component of hemoglobin.
Erythropoietic Protoporphyria (EPP): Most cases of EPP are caused by autosomal recessive inheritance involving mutations in the FECH gene. This means that an individual must inherit a mutated gene from both parents to be affected.
X-linked Protoporphyria (XLP): XLP is caused by increased activity of ALAS2 in erythroid cells due to a gain-of-function mutation in the ALAS2 gene.
Medicine Used
Afamelanotide (Scenesse): This is a synthetic melanocortin receptor agonist that stimulates melanin production, providing protection against sunlight. It's often used to reduce photosensitivity.
Beta-carotene: High doses can provide some protection against sunlight by acting as an antioxidant. However, effectiveness varies.
Cholestyramine: Can help remove protoporphyrin from the body, reducing liver issues.
Ursodeoxycholic acid (UDCA): May be used to manage liver dysfunction.
Iron supplementation: May be necessary if anemia is present.
Pain management: Analgesics are used to manage acute pain associated with photosensitivity episodes.
Liver transplantation: In severe cases of liver failure, liver transplantation may be necessary.
Is Communicable
No, EPP and XLP are not communicable. They are genetic disorders and cannot be spread from person to person.
Precautions
Sun avoidance: The most important precaution is minimizing sun exposure.
Protective clothing: Wear long sleeves, hats, gloves, and sunglasses.
Sunscreen: Use broad-spectrum sunscreens with high SPF, although their effectiveness may be limited.
Window film: Apply window film to block UV radiation in cars and homes.
Light source awareness: Be aware that some artificial light sources can also trigger symptoms. Use appropriate lighting in homes and workplaces.
Liver monitoring: Regular monitoring of liver function is important, especially for individuals at risk of liver disease.
Genetic counseling: Genetic counseling is recommended for affected individuals and their families.
How long does an outbreak last?
An "outbreak" is not an applicable term for EPP and XLP. These are chronic conditions. The acute symptoms of photosensitivity typically last for hours to days following sun exposure. The *chronic* aspects of the disease, such as liver complications, are ongoing and require long-term management.
How is it diagnosed?
Clinical evaluation: Assessment of symptoms, particularly photosensitivity.
Blood tests: Elevated levels of protoporphyrin in red blood cells and plasma are characteristic.
Urine and stool tests: May be used to assess porphyrin levels.
Genetic testing: Identifies mutations in the FECH gene (for EPP) or *ALAS2* gene (for XLP).
Liver biopsy: May be performed to evaluate liver damage.
Timeline of Symptoms
Early childhood: Photosensitivity typically begins in early childhood, often within the first few years of life.
Acute episodes: Pain, burning, and itching begin within minutes of sun exposure.
Chronic progression: Repeated episodes can lead to skin changes, scarring, and potentially liver complications over time.
Variable severity: The severity of symptoms can vary significantly between individuals and may fluctuate over time.
Important Considerations
Early diagnosis: Early diagnosis is crucial for implementing preventative measures and minimizing long-term complications.
Individualized management: Treatment plans should be tailored to the specific needs of each individual, considering the severity of symptoms and the presence of liver disease.
Psychological support: The chronic nature of the condition and the impact on daily life can lead to psychological distress. Support groups and counseling may be beneficial.
Medication safety: Certain medications can exacerbate porphyria symptoms. It's important for affected individuals to inform their healthcare providers about their condition.
Research: Ongoing research is aimed at developing new and more effective treatments for EPP and XLP.