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Porphyria
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Porphyria

Pronounced: por-fir-E-ah

En Español (Spanish Version)

Definition

The term porphyria refers to a group of at least eight disorders that differ clinically from each other, but all share the same problem of accumulation of "porphyrins" or "porphyrin precursors" in the body. Porphyrin is a building block for heme. And heme is the iron-containing part of the hemoglobin in red blood cells that carries oxygen to all of the organs in our body.

Hemoglobin Transporting Oxygen

Hemoglobin - anemia

© 2008 Nucleus Medical Art, Inc.

The build up of the porphyrins in the body cause symptoms in two major organ systems: the nervous system and the skin.

  • Effects on the nervous system occur in the acute porphyrias. The diagnosis is often delayed because the symptoms are nonspecific. Some patients have attacks in which the nerves of the body do not function properly. Abdominal pain and weakness can be a symptom.
  • Skin manifestations can include burning, blistering, and scarring of sun-exposed areas.

The terms "porphyrin" and "porphyria" are derived from the Greek word "porphyrus" meaning purple. Urine from some porphyria patients may be reddish in color due to the presence of excess porphyrins and related substances, and the urine may darken after standing in the light. Excess porphyrins are also excreted in the stool.

Some types of porphyria have onset in early childhood, some at puberty, and others during adulthood. The onset most frequently occurs between the ages of 20 and 40. The disease affects men less often than women, in whom attacks are related to the menstrual cycle. Long periods may separate attacks, which can be precipitated by drugs, infections, alcohol consumption, and dieting.

Causes

Most types of porphyrias are inherited. One subtype, porphyria cutanea tarda, is acquired. The porphyrias may be inherited as either autosomal dominant (caused by inheriting one abnormal copy of the gene) or autosomal recessive (requires inheritance of two abnormal genes) traits depending on which type of porphyria is involved.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. The most common risk factor for porphyria is having a family member with this disease. Also, Caucasians are at greater risk than Blacks or Asians.

If you have porphyria, certain factors can increase your risk of a porphyria attack. These include: drugs, chemicals, alcohol, dieting, and sunlight. Triggers for specific types of porphyria are listed below:

Acute Intermittent Porphyria

  • Drugs, such as:
    • Barbiturates
    • Sulfa drugs
    • Seizure drugs
    • Steroid hormones such as:
      • Estrogen
      • Progesterone
  • Hormonal changes related to the menstrual cycle
  • Weight-loss diets or fasting
  • Infections
  • Alcohol
  • Stress
  • Surgery
  • Cigarette smoke

Porphyria Cutanea Tarda

  • Iron
  • Alcohol
  • Estrogens
  • Hydrocarbons
  • Certain pesticides or chemicals

Erythropoietic Protoporphyria

  • Sunlight
  • Weight-loss diets or fasting

Congenital Erythropoietic Protoporphyria

  • Sunlight

Symptoms

Porphyria can cause skin or nervous system problems. Specific symptoms depend on the type.

Acute Intermittent Porphyria (AIP)

Inherited autosomal dominant trait

Nervous system symptoms usually occur after puberty. Gastrointestinal symptoms are caused by nerves that affect the intestinal tract. Attacks can last from days to weeks. Symptoms of future attacks resemble the initial episode and may include:

Porphyria Cutanea Tarda (PCT)

The most common porphyria; most are not inherited, but some are autosomal dominant trait.

Symptoms may include:

  • Sun sensitivity
  • Sun-exposed skin is fragile
  • Minor injury may damage the skin
  • Blisters on the face, hands, arms, feet, and legs
  • Skin heals slowly
  • Skin susceptible to infection
  • Skin thickens and scars
  • Skin color changes
  • Excess hair growth
  • Reddish urine in infancy or childhood

Erythropoietic Protoporphyria (EPP)

Inherited as an autosomal dominant trait.

Symptoms may include:

  • Sun sensitivity
  • Redness or swelling, but usually no blisters
  • Itching or burning sensation
  • Long-term skin and nail changes
  • Gallstones

Congenital Erythropoietic Protoporphyria (CEP)

Extremely rare, inherited autosomal recessive trait

Symptoms may include:

  • Reddish urine, in infancy
  • Sun sensitivity, beginning in early infancy
  • Sun-exposed skin is fragile
  • Blisters on sun-exposed skin
  • Blisters open and are prone to infection
  • Skin color may change
  • Skin thickens
  • Excess hair growth
  • Scarring
  • Reddish-brown teeth
  • Enlarged spleen
  • Hemolytic anemia

Diagnosis

The doctor will ask about symptoms as well as medical and family history. A physical examination will also be done.

Tests differ for the various types of porphyria, and may include blood, urine, and/or stool tests to check for excess porphyrin or to check for a specific enzyme deficiency. In some cases specific genetic testing may be available as well.

Treatment

For all types of porphyria, treatment includes the following:

  • Avoiding known triggers and drugs that can precipitate an attack
  • Eating a high-carbohydrate diet

Porphyria that affects the skin require special attention to protect the skin from injury and/or infection.

Specific treatment depends on the type of porphyria.

Acute Intermittent Porphyria

You may need to be hospitalized during an attack. In the hospital, you may be given the following:

  • Heme by vein (intravenous) in the form of hematin, heme albumin, or heme arginate
  • Glucose by vein
  • Drugs to control symptoms such as pain, nausea, anxiety, and insomnia

Porphyria Cutanea Tarda

Treatment may include:

  • Blood removal weekly to monthly
  • Low doses of antimalarial drugs, such as:
    • Chloroquine (Aralen Phosphate)
    • Hydroxychloroquine (Plaquenil)
  • Radiology imaging to monitor for increased risk of liver cancer

Erythropoietic Protoporphyria

Treatment may include:

  • Oral beta-carotene
  • Maintaining normal iron levels with food or supplements
  • Medication to aid excretion of porphyrins in stool, such as:
    • Activated charcoal
    • Cholestyramine
    • Blood transfusions
    • Heme by vein in the form of hematin, heme albumin, or heme arginate
    • Spleen removal

Congenital Erythropoietic Protoporphyria

Treatment may include:

Prevention

Genetic testing may identify people at risk for porphyria. If there are people in your family with the diagnosis of porphyria, you may be eligible for testing if that family member has had genetic testing and that testing showed a change in the DNA; that change can then be looked for in you.

A genetic counselor can review your family history and risks for this disorder in you and your offspring and discuss appropriate testing that is available for you.

Although the genetic mutation cannot be corrected, attacks can be anticipated, prevented, or controlled. Steps to avoid porphyria attacks and complications include the following:

  • Avoid drugs and other triggers
  • Protect skin from injury or infection

RESOURCES:

American Liver Foundation
http://www.liverfoundation.org

National Institute of Diabetes and Digestive and Kidney Diseases
http://www2.niddk.nih.gov

National Organization for Rare Disorders, Inc.
http://www.rarediseases.org/.

CANADIAN RESOURCES:

Canadian Liver Foundation
http://www.liver.ca/Home.aspx

Canadian Organization for Rare Disorders
http://www.cord.ca/

References:

The American Phorphyria Foundation website. Available at: http://porphyriafoundation.com .

Beers MH. The Merck Manual of Medical Information . Home Edition, 2nd ed. Simon and Schuster, Inc; 2003.

Cecil Textbook of Medicine . 21st ed. WB Saunders Co; 2000.

Conn's Current Therapy 2001 . 53rd ed. WB Saunders Co; 2001.

Goldman L. Cecil Textbook of Medicine . 22nd ed. Philadelphia, PA: Saunders; 2004.

Harrison's Principles of Internal Medicine . 14th ed. The McGraw-Hill Companies; 2000.

Medline Plus website. Available at: http://www.nlm.nih.gov/medlineplus/porphyria.html .



Last reviewed October 2007 by Mark A. Best, MD, MPH, MBA, FCAP, FASCP

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.


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