Erythropoietic Protoporphyria

Also known as EPP, it is a rare inherited porphyrin metabolism disorder that affects between one in 200,000 and one in 750,000 people. This disorder causes a chemical known as protoporphyrin IX to accumulate in the skin. When the skin is exposed to the sun, these molecules undergo a chemical reaction that results in swelling, excruciating pain and scarring.

The pain is sometimes described as like having hot needles stuck into the skin. The lifelong pain experienced by these patients can be so severe that they require continuous treatment with analgesics to cope with the incessant pain. Typically, these patients become socially isolated because of the lack of an efficacious treatment and their need to continuously avoid sunlight.

Sun avoidance by remaining indoors or wearing sun protective clothing including cotton gloves and a wide brimmed hat is the first line in EPP management. Drugs such as B-carotene, cysteine and cimitedine have been used and because the disease is inherited, genetic counselling is recommended.

Since sun avoidance is recommended, patients lead lives where they are in the sun for very limited time. This can prevent normal social activities and the intense pain that is experience interferes with normal daily activities and can prevent adequate sleep.

Afamelanotide (CUV1647) is currently in Phase III trials for EPP in Europe and Australia.

It is hoped that with regular use of afamelanotide (CUV1647), EPP patients will become more resistant to the effects of the sun and be able to lead more normal lives.

For more information on EPP, please see the Clinuvel Photoprotection EPP page.

Clinuvel Pharmaceuticals is a member of the American Porphyria Foundation. Please click here to view the website  

References

Murphy GM. "Diagnosis and Management of the Erythropoietic Porphyrias", Dermatologic Therapy 2003;16:57-64
Thunell S, Harper P, Brun A. "Porphyrins, Porphyrin Metabolism and Porphyrias. IV. Pathophysiology of Erythropoietic Protoporphyria - Diagnosis, Care and Monitoring of the Patient". Scand J Clin Lab Invest 2000;60:581-604

Todd DJ. "Clinical Implications of the Molecular Biology of Erythropoietic Protoporphyria", J Eur Acad Dermatol Venerol 1998;11:207-13