Porphyrias are a group of rare disorders passed down through families, in which an important part of hemoglobin, called heme, is not made properly. Heme is also found in myoglobin, a protein found in certain muscles.
Normally, the body makes heme in a multi-step process. Porphyrins are made during several steps of this process. Patients with porphyria have a deficiency of certain enzymes needed for this process. This causes abnormal amounts of porphyrins or related chemicals to build up in the body.
There are many different forms of porphyria. The most common type is porphyria cutanea tarda (PCT).
Drugs, infection, alcohol, and hormones such as estrogen may trigger attacks of certain types of porphyria.
Symptoms
Porphyrias involve three major symptoms:
Abdominal pain or cramping (only in some forms of the disease)
Problems with the nervous system and muscles (seizures, mental disturbances, nerve damage)
Attacks can occur suddenly, usually with severe abdominal pain followed by vomiting and constipation. Being out in the sun can cause pain, sensations of heat, blistering, and skin redness and swelling. Blisters heal slowly, often with scarring or skin color changes. They may be disfiguring. Urine may turn red or brown after an attack.
Other symptoms may include:
Muscle pain
Muscle weakness or paralysis
Numbness or tingling
Pain in the arms or legs
Pain in the back
Personality changes
Attacks can sometimes be life threatening, producing:
Your doctor will perform a physical exam, which includes listening to your heart. You may have a fast heart rate (tachycardia). The doctor may find that your deep tendon reflexes (knee jerks or others) do not work properly.
Blood and urine tests may reveal kidney problems or other problems. Special tests can measure porphyrins in the blood.
Fluids and glucose to boost carbohydrate levels, which helps limit the production of porphyrins
Removal of blood (phlebotomy)
Depending on the type of porphyria you have, your doctor may tell you to:
Avoid all alcohol
Avoid drugs that may trigger an attack
Avoid injuring the skin
Avoid sunlight as much as possible and use sunscreen when outside
Eat a high-carbohydrate diet
Expectations (prognosis)
Porphyrias are life-long diseases with symptoms that come and go. Some forms of the disease cause more symptoms than others. Proper treatment and avoidance of triggers can help prolong the time between attacks.
Respiratory failure (due to weakness of chest muscles)
Scarring of the skin
Calling your health care provider
Seek medical attention as soon as you have signs of an acute attack. Talk to your doctor about your risk for this condition if you have a long history of undiagnosed abdominal pain, muscle and nerve problems, and sensitivity to sunlight.
Prevention
Genetic counseling may benefit people who want to have children and who have a family history of any type of porphyria.
References
Anderson K. The porphyrias. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 229.
Wiley JS, Moore MR. Heme biosynthesis and its disorders: porphyrias and sideroblastic anemias. In: Hoffman R, Benz EJ Jr., Shattil SJ, et al, eds. Hoffman Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone Elsevier; 2008:chap 38.
Review Date:
2/28/2011
Reviewed By:
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
