Erythropoietic protoporphyria is a genetic disorder that predisposes people to extreme sensitivity to sunlight. The condition causes exposed skin to become irritated, inflamed, swollen, and painful. Blisters and permanent scars may develop on the hands or face. In addition, some children and adults with erythropoietic protoporphyria suffer potentially serious gallbladder and liver complications. There is no clear cure for the disorder, but taking steps to minimize sun exposure and receiving regular medical checkups can limit the risks of severe health problems.
Decades of genetic research have uncovered the underlying cause of erythropoietic protoporphyria. An inheritable mutation impairs the function of an enzyme called ferrochelatase, which normally helps to build hemoglobin and other blood components. Abnormal enzymes result in a buildup of protoporphyrin in bone marrow, the bloodstream, and body tissue. Protoporphyrin is extremely light-sensitive, and buildups near the skin trigger inflammation when the body is exposed to sunlight.
When a person with erythropoietic protoporphyria spends a short amount of time in the sun, his or her skin may feel itchy and tender. Spending more than about one hour outdoors can cause redness, swelling, and painful burning sensations. The longer a person stays in the sun, the worse symptoms tend to become. Multiple, extended periods of sunlight exposure can cause blistering and open lesions that eventually become scars.
A small number of people with erythropoietic protoporphyria develop liver problems. Protoporphyrin can build up in bile and liver tissue, which can result in gallstones or minor hepatitis. Eventual liver failure is possible if the underlying condition is not diagnosed and treated correctly.
A doctor can diagnose erythropoietic protoporphyria by carefully evaluating symptoms and performing a series of blood and bile tests. If unusually high levels of protoporphyrin are found, other problems such as eczema, allergies, and lupus can be ruled out. Ultrasounds and x-rays may also be performed if the physician suspects liver damage or gallstones.
Preventing overexposure to sunlight is the key component of erythropoietic protoporphyria treatment. Patients are instructed to wear protective clothing, apply sunscreen, and limit the time they spend outdoors. In addition, they may be encouraged to tint the windows of their cars and homes to further prevent exposure. Topical medications may be prescribed to ease itching and burning symptoms, and oral drugs such as beta-carotene might be used to help reduce light sensitivity.
If a patient has gallstones or other liver complications, surgery may be necessary to repair the problem and restore normal functioning. Most people are able to recover from acute liver problems following surgical care, but there are risks that stones or tissue inflammation may return in the future. Regular checkups are important to make sure symptoms are caught before they become serious.