Porphyria

Porphyria General Information

Porphyria is the generic medical term given to a complex of 8 disorders. While they are considerably different from one another, all of them are characterized by the accumulation of porphyrins and porphyrin precursors in the organism. These are substances that are found in the human organism under normal circumstances as well, however they do not accumulate. The type of substance that is accumulated varies according to the type of the affection.

The terms used to denominate the disease derives from the Greek term “porphyrus” which can be translated into “purple”, and is likely to have been chosen due to the coloring of some bodily fluids in an affected patient. For example, in some of the patients the urine may take a reddish color, due to the excess porphyrins and related fluids. Also, the urine may darken after it has been exposed to light.

Each type of Porphyria is characterized by a deficiency of a specific enzyme, which are involved in heme synthesis. The heme is important to many functions in the organism, and is generally found in large quantities in blood, bone marrow and in the liver. Typically encountered under the form of hemoglobin in blood and in the bone marrow, it is also present in other tissues where it fulfils different functions. The types of the disease are classified according to the deficient enzyme. The affection is typically inherited, and factors such as chemicals, foods or sun exposure can affect the severity of the symptoms.

Porphyria Symptoms

In the case of hepatic variations of Porphyria, the disease affects primarily the nervous system. In such cases the affected patients will experience abdominal pain, vomiting, seizures, acute neuropathy and mental disturbances. Anxiety, depressions, hallucinations and paranoia are common occurrences in such cases. As the autonomic nervous system is also affected, cardiac affections such as tachycardia and arrhythmias may develop. In some cases the pain associated with the affection may be severe, and can be acute or chronic. In most cases the patient is also affected by constipation or diarrhea.

It has been noted that not all cases of Porphyria are genetically transmitted. They can be caused by other physical affections, and in such cases the patient will also present symptoms that are common to those affections. In the case of cutaneous Porphyria (variations of the disease that affect the skin), he patient is likely to experience an increase in photosensitivity, itching, blistering and swelling. Necrosis of the skin and gums has also been encountered in many such cases. The patients may also present an increase in hair growth in some areas (particularly on the forehead). Such cases are characterized by the lack of abdominal pain.

In some cases, the accumulated porphyrin precursors are excreted through the urine. The color of the patient’s urine will change to a reddish or brownish hue, darkening after exposure to light. Pink or purple coloring of the urine has also been observed. The patient’s teeth and fingernails may also change their color to reddish, in cases where there are large accumulations of porphyrin precursors in those areas. As there are many variations of this affection, and given the rarity of the condition, it is possible that initially the disease is misdiagnosed. However, further testing will allow the examining health care specialist to correct the diagnosis and properly treat the patient.

Porphyria Treatment

It is advised that in cases of undiagnosed Porphyria, but with a high degree of certainty, empirical treatment is administered as acute attacks are often lethal. The patient should undergo a diet with a high concentration of carbohydrates and if the attack has already begun, the patient should be administered a 10% glucose infusion.

In cases of acute Porphyria the treatment of choice consists of administration of Hematin and Heme Arginate. It is imperative that the drug therapy is begun as soon as possible, preferably at the beginning of an attack in order for the medication to be effective, although it has been noted that the effectiveness may be reduced in some patients. These drugs are not prescribed as a curative agent, but they are able to reduce the intensity and duration of an attack. The drugs are based on heme-like substances that act by inhibiting the accumulation of certain precursors, most of them toxic for the human organism. There are some severe side effects associated with use of these drugs; however the incidence rate is rare.

In the case the patient presents weakness or low concentrations of blood sodium, the therapy should include Heme Arginate or Hematin on a regular basis – these symptoms may signal the onset of SIADH (the syndrome of inappropriate antidiuretic hormone) or other severe affections, such as bulbar paresis, respiratory paralysis or peripherial nervous system damage. It is highly advised that in cases of Porphyria where attacks are caused by drugs and medication, therapy with those substances is immediately ceased. If the attacks are caused by an infection, immediate and vigorous treatment of the infection is imperative.

In most Porphyria cases, pain is extremely severe and needs to be controlled as soon as possible. Opiate class drugs are generally used to control the pain until further progress is made with the therapy. If the patient is nauseous, Phenothiazine drugs may aid in relieving this symptom, however in some cases it is not treatable. Hot baths and showers may be employed to reduce nausea, but special care should be taken to avoid any burns or falls.

If depression is a sign of the disease, it is typically treated with anti-depressants; however some of the drugs in this class are porphyrinogenic, so the specialized health care professional administering or prescribing the medication should avoid such drugs that may worsen the patient’s health condition. Such cases are often accompanied by seizures, and medication more often than not aggravates the disease. In such cases the health care professionals may have difficulties in deciding upon an appropriate treatment. Barbiturates should altogether be avoided. It has been noted that some Benzodiazepines may be safe for use, and newer medication such as Gabapentin may provide a means of controlling seizures without complications. Magnesium sulfate or bromides have been used to some extent with positive results, however if the condition worsens and the patient is affected by status epilepticus additional medication must be used in conjunction with magnesium in order to become effective.