Porphyria is a name designating several nervous system disorders caused by deficiency of different enzymes. The affected enzymes are critical in producing a chemical compound called heme, a component whose presence in the blood is critical. Heme is necessary in certain proteins, holds a supply of iron, and causes our blood to be red.
Porphyria causes excessive accumulations of a normal body chemical called porphyrin, hence its name.
The more acute porphyrias may cause vomiting and stomach or abdominal pain, nerve pain or numbness, seizures and overall weakness. Tachycardia or arrhythmia may occur. The individual may have either constipation or diarrhea. Mental disturbances such as anxiety, depression, paranoia or even hallucinations may be experienced. There is almost always an increased sensitivity to light.
There is also an increased sensitivity to light in cutaneous porphyrias which affect the skin. In this type, patients also can have blisters, swelling, itching, cell death in gums and skin, and sometimes hair will grow in unusual spots on the body. Cutaneous types of porphyria are much more common than the acute.
In some types of porphyria, urine may take on a dark color of brown, purple, or red if exposed to light.
Porphyria is diagnosed through blood, stool and urine tests. The tests will measure accumulation of porphyrins, with further tests to establish affected enzymes if such accumulation is shown.
Persons suffering from acute porphyrias can experience very sudden life-threatening attacks. In that instance, they must be admitted to the hospital where they receive iv fluids, medications to suppress production of porphyrin, and a special diet with high carbohydrate values. Drugs used to prevent such attacks or halt an acute attack early on are hematin, and heme arginate. A high carbohydrate diet is recommended in acute porphyria as a matter of course. Glucose infusion is sometimes utilized when necessary.
In cutaneous porphyrias, patients must use high powered sunscreen and wear dark glasses as well as clothing that will protect from too much sunlight. Portions of their blood will be collected by phlebotomy methods in order to reduce amounts of stored iron.
The pain associated with porphyrias can be extremely severe, so opioids are often prescribed. Anti-nausea drugs are usually given, due to the overwhelming nausea these patients often experience.
A person with porphyria is especially prone to infection, so cleanliness and an avoidance of persons with communicable disease is a primary consideration. Illness or infection can often set off an acute attack.
Depending on an individual’s symptoms, antiseizure medication or pharmacotherapeutic drugs for depression or mental instability caused by nerve deterioration may be needed. The prescribing physician must be careful in dispending psychotropic drugs, because some affect porphyria patients much differently than they affect other patients.
Acute porphyria can be a deadly disease; however, if diagnosed early and appropriately treated, patients can live a satisfying, productive life.
Signet/Mosby Medical Encyclopedia
National Institute of Health