Porphyria

Porphyria

Porphyria is a group of disorders that cause the body to produce too many porphyrins.

Porphyrins make up an important part of your blood that carries oxygen (hemoglobin).

Porphyria can affect your skin and your nervous system.

The nervous system is made up of the brain, spinal cord, and all the nerves that send and receive signals from the rest of your body.

Pathophysiology

Acute hepatic porphyrias (acute intermittent porphyria, variegate porphyria, and hereditary coproporphyria) are autosomal dominant hereditary disorders that manifest as acute or subacute, severe, life-threatening neuropathy.

The basic genetic defect is a 50% reduction in porphobilinogen deaminase activity (acute intermittent porphyria), protoporphyrinogen-IX oxidase (variegate porphyria), and coproporphyrinogen oxidase (coproporphyria), resulting in abnormalities of heme biosynthesis.

In the presence of sufficient endogenous or exogenous stimuli (e.g., drugs, hormones, menstruation, starvation), this partial deficiency may lead to clinical manifestations, including peripheral neuropathy, autonomic dysfunction, skin symptoms, and CNS abnormalities. 

Pathologic involvement of the autonomic nervous system (degeneration of the vagus nerve and sympathetic trunk) may explain certain features of acute attacks, including abdominal pain, severe vomiting, constipation, intestinal dilatation and stasis, persistent sinus tachycardia (100 to 160 minutes), labile hypertension, postural hypotension, hyperhidrosis, and sphincteric bladder problems.

There are two types of porphyrias:

• Cutaneous porphyrias. These cause skin symptoms.
• Acute porphyrias. These cause mostly nervous system symptoms. In some cases, they cause both nervous system and skin symptoms. Acute porphyrias can damage your body. They can lead to high blood pressure, kidney failure, and liver cancer.

What are the causes?

Porphyria is usually passed from parents to children (inherited). It can be triggered by:

• Emotional and physical stress.
• Chemicals.
• Certain medicines (sulfonamides, sedatives).
• Drinking alcohol.
• Menstrual hormones.
• Birth control pills.
• Fasting.
• Infections.
• Exposure to the sun.
• Smoking.
• Emotional and physical stress.

What increases the risk?

You are more likely to develop this condition if you have a family history of porphyria.

What are the symptoms?

Symptoms of this condition can develop over hours or days. They can last for days or weeks. Both cutaneous and acute porphyrias can cause the skin to blister, itch, and swell when it is exposed to sunlight. Acute porphyrias can also cause:

• Pain in the chest, abdomen, limbs, or back.
• Muscle numbness, tingling, paralysis, or cramping.
• Vomiting or difficulty passing stool (constipation).
• Personality changes.
• Feeling that people are “out to get you” (paranoia).
• Seeing and hearing things that are not there (hallucinations).
• Confusion.
• Anxiety.
• Depression.
• Violent behavior.
• Unstable vital signs.
• Excessive sweating.
• Painful urination and other bladder problems. In some cases, urine may turn red or dark when exposed to light.
• Fever.
• Restlessness.
• Tremors.
• Vision problems, including blindness.
• Seizures.

How is this diagnosed?

Porphyria is diagnosed with blood, urine, and stool tests.

How is this treated?

Treatment is specific to your symptoms. You may need treatment at a hospital if your attack is severe. Medicines to help pain and nausea may be given through an IV line. Other medicines may include:

• Hematin, for iron.
• Anti-seizure medicines.
• Medicines to treat mental (psychiatric) symptoms.
• Intermittent bloodletting (phlebotomy).
• Glucose.

Follow these instructions at home:

• Talk with your health care provider about changing your diet. Your new diet may need to be high in carbohydrates and low in salt and fat.
• Avoid fasting and dieting.
• Avoid stress.
• Do not stay in the sun for too long.
• Drink plenty of water, especially if your condition is treated with phlebotomy.
• Do not drink alcohol.
• Do not use any products that contain nicotine or tobacco, such as cigarettes and e-cigarettes. If you need help quitting, ask your health care provider.
• Take over-the-counter and prescription medicines only as told by your health care provider. Do not take any new medicines without first asking your health care provider about them.
• Keep all follow-up visits as told by your health care provider. This is important.

Seek Additional Information

• American Porphyria Foundation: www.porphyriafoundation.com  
• National Digestive Diseases. You may:
  • Visit the web site: www.niddk.nih.gov  
  • Send an e-mail to healthinfo@niddk.nih.gov  

Contact a health care provider if:

• Your symptoms return.
• You have a fever.

Summary

• Porphyria is a group of disorders that cause the body to produce an excess of chemicals known as porphyrins.
• Porphyrins make up an important part of your blood that carries oxygen (hemoglobin).
• It can affect the skin and the nervous system.
• You are more likely to develop this condition if you have a family history of porphyria.
• Symptoms of porphyria can develop over hours or days. They can last for days or weeks.