What is general porphyria?
Porphyria is a group of at least 8 different diseases. They are rare, inherited, metabolic disorders that result from a deficiency of one of the enzymes necessary for the production of heme. Heme is a deep red blood pigment that is a part of hemoglobin, necessary for the transportation of oxygen to cells in the body.
If any step in the production of heme is blocked, an intermediate chemical accumulates in the cell and results in oxygen depletion. Those intermediate chemicals are knows as porphyrins
and porphyrin precursors
The common feature in all porphyria is the accumulation in the body of porphyrins or porphyrin precursors. The type of porphyrin and porphyrin precursors that accumulate determine the type of porphyria.
What is hepatic porphyria?
Hepatic porphyria is a form of porphyria characterized by enzyme deficiencies in the liver. Hepatic
means “pertaining to the liver.” Acute hepatic porphyria are characterized by attacks of the organs in the large cavity of the torso and the corresponding parts of the nervous system. They may or may not have skin manifestations (such as lesions).
There are different types of acute
hepatic porphyria, including:
- Acute intermittent porphyria (AIP)
- Variagate porphyria
- Hereditary coproporphyria (HCP)
- Hereditary deficit of delta-aminolevulinic acid dehydratase
In addition, there are different types of chronic
hepatic porphyria, including:
- Porphyria cutanea tarda
- Hepatoerythropoietic porphyria
Chronic hepatic porphyria present inflammation of the skin as a result of exposure to light, such as sunlight. The inflammation may be characterized by blisters on the skin.
What are the symptoms of hepatic porphyria?
All acute hepatic porphyria are accompanied by attacks of the internal organs and the autonomic nervous system. These attacks manifest as:
- Intense abdominal cramping over one to two weeks
- Neurological symptoms such as muscle weakness, sensory loss, or convulsions
- Psychological symptoms such as irritability, anxiety, auditory or visual hallucinations, confusion
Variagate porphyria and hereditary coproporphyria may also result in inflammation of the skin.
Unlike the acute hepatic porphyrias, chronic hepatic porphyria do not manifest with attacks of the internal organs or autonomic nervous system. Instead, chronic hepatic porphyrias are characterized by lesions of the skin, particularly in those areas exposed to sunlight (such as the face and hands).
What causes an acute hepatic porphyria attack?
Attacks are most commonly triggered by outside factors such as stress, alcohol, infections, a diet too low in calories, and some types of medicines (known as porphyrinogenic drugs). Internal factors, such as hormonal changes, may also trigger an attack, and sometimes attacks are linked to menstrual cycles.
How are the hepatic porphyria diagnosed?
Because the symptoms of the various porphyria may resemble symptoms of other disorders, diagnosis may be difficult. In the end, however, a diagnosis is based on:
- Elevated concentrations of ALA
- Elevated concentrations of PBG
Presence of porphyrins in urine, stool, or blood.
The exact type of porphyria is determined by enzyme measurement and assessment of genetic mutations.
What treatment options are available for hepatic porphyria?
Treatment is specific to the type of porphyria. Most treatments focus on pain management and reversing the cause of the acute attack, as well as prevention of a neurological crisis.
Hemin is usually administered intravenously. Glucose may be administered in those persons with a severe reduction in caloric intake.
In severe cases resulting in a neurological crisis, a liver transplant may be necessary.
Where can I find more information about hepatic porphyria?