Link to original: http://sphynxcatvp.nocturna.org/health/sc-porphyria.html
Porphyria is one of those ailments that gets pegged as "the vampire disease" because the porphyria forms affecting the skin have photosensitivity as one of the side effects. While the photosensitivity may be a shared problem, the effects of it are not. This article will provide an overview of the porphyrias and explain why someone with porphyria isn't necessarily vampiric.
What are the porphyrias?
Despite most non-medical people thinking porphyria is one disease, there are actually SEVERAL variants - some more rare than others - and typically classified by whether they predominantly affect the skin, the liver/nervous system, or a combination of the two. Porphyrias are characterized by the buildup of "porphyrins", a component of Heme, which is itself a component of red blood cells.
What are the symptoms of the porphyrias?
If it's early in the process the accumulation of excess components ("metabolite intermediates" such as aminolevulinic acid and porphobilinogen) will generate acute nerve and abdominal pain, vomiting, muscle weakness, respiratory failure, high blood pressure, seizures and mental symptoms such as hallucinations, depression, anxiety, and paranoia. Rapid heart rate and other cardiac issues may develop as the autonomic nervous system gets involved. Pain can be VERY severe, and sometimes chronic if it's undiagnosed for a long period of time. Constipation or diarrhea may be present. Irritability and insomnia may also be present.
Acute porphyria comes with an increased risk of primary liver cancer and the patient MUST be monitored for this risk their whole life.
Cutaneous / Skin related:
If the defect is later in the heme production process, the porphyrins will accumulate in the skin and cause photosensitivity (photodermatitis), blisters, damage to (and possible tissue death of) the skin and gums, itching, and swelling. Sometimes there is increased hair growth on areas such as the forehead. Abdominal pain is rarely present, which which will distinguish the skin-only forms from the others.
Urine color - especially during an attack - may be pink, reddish or brown color on exposure to sunlight or fluorescent lights (since fluorescent lights give off UV, it is possible that this is is a photoreaction reaction to the UV.) Sometimes the urine may even have a purple tint. Patients may have seizures due to the nerve involvement of some forms - however many seizure medications will make the problem WORSE, not better.
Pain is often "out of proportion" to the symptoms, and because of this - especially for women - will run the risk of doctors thinking the patient is just "looking for drugs." Very severe ("intractable") pain is TYPICAL for acute porphyria attacks, and doctors need to be told that porphyria is either a suspected or known diagnosis.
What causes porphyrias?
Porphyrias are a set of syndromes characterized by a defect in the body's process of manufacturing "Heme", part of the hemoglobin molecule in red blood cells. The principle issue in the porphyrias isn't the defect itself (people without porphyria can still have heme production defects here and there without developing porphyria symptoms) - the problem comes in the accumulation of porphyrins, which are toxic to tissues in high concentrations (and are what lead to many of the symptoms.) Four of the eight enzymes in the heme production chain are in the mitochondria, and the other four are in the intracellular fluid. Defects with any of these can lead to porphyrin buildup, and thus one of the forms of porphyria. Where in the chain the defects occur will determine what symptoms the patient has.
Porphyrias in general are fairly rare, but some types are more rare than others. Normally, most porphyrias are inherited (and it tends to run in families), but on rare occasions it can be acquired as a result of environmental toxins, infection (such as hepatitis c) or other liver damage. The different porphyrias include:
- Doss porphyria / plumboporphyria (very rare)
- Acute intermittent porphyria
- Hereditary coproporphyria
- Variegate porphyria
- Erythropoietic porphyria
- Porphyria cutanea tarda
- Congenital erythropoietic porphyria (Gunther's disease; also very rare)
They can be broken down into the following types:
- Hepatic - Liver/Nervous System: Acute Intermittent Porphyria, Plumboporphyria/Doss Porphyria
- Skin: Porphyria Cutanea Tarda, Congenital Erythropoeietic, Erythropoietic
- Mixed: hereditary coproporphyria, Variegate Porphyria
Or whether they are acute or chronic:
- Acute: Acute Intermittent Porphyria, Doss/Plumbo, Hereditary Coproporphyria, and Variegate Porphyria
- Chronic: Congenital erythropoietic porphyria, erythropoietic porphyria, and porphyria cutanea tarda
For those who are more medically inclined, Medscape has a chart illustrating the heme production process; the red flattened diamond shapes in the various steps indicate what form of porphyria is the result of a defect in that particular part of the process. [Click to see the chart] [Zane note: This link no longer works.]
How are the porphyrias diagnosed?
Porphyrias in general are RARE conditions - as a result, many hospitals and doctors will not have the immediate knowledge to recognize it on the spot, and thus diagnosis and treatment may be delayed if they spend time chasing an unrelated diagnosis.
Sampling for diagnostics (blood, urine AND stool) MUST MUST MUST be done DURING an acute porphyria attack, not after, and samples must be both kept out of light and properly preserved or refrigerated otherwise a false negative may result. The first things the medical professionals should be looking for is the presence - and amount - of "PBG" (porphobilinogen) and ALA (aminolevulinic acid).
Diagnostic bloodwork will indicate whether there are any particular organ issues going on (such as liver damage, jaundice, hemochromatosis, hepatitis-C, etc.), and CT scanning or MRI rules out other causes of excruciating abdominal pain, such as ruptured blood vessels, punctured organs, colon issues, tumors, and so on.
Further diagnostic tests of affected organs may be needed, as well as nerve conduction studies (to see how well the nerves are working) or a liver ultrasound to see how much other damage is going on.
There are two basic types of urine tests - one is where they add a few drops of urine to a reacting chemical, and it turns red. There's the "Hoesch Test" and the "Watson-Schwartz test"; the Watson-Schwartz test is an older method.
The other basic test is to expose the urine to bright sunlight for several hours (I've seen up to 24 hours mentioned) - and it will darken to a dark red or mahogany color, sometimes with sediment.
What will aggravate porphyria symptoms?
Periods of hormonal changes will commonly set off an attack: Puberty, menstruation, birth control pills (starting OR stopping), pregnancy, etc.
Barbiturates, sulfonamide; enzyme inducing anticonvulsants, carbamazepine, phenytoin, phenobarbitone, primodone, oral contraceptive pill; also, diphenylhydantoin, rifampicin, chlordiazepoxide, griseofulvin and ergots. Merck.com has a PDF with a quick-reference list of safe-vs-unsafe drug types for porphyria patients. [Click to see the PDF]
Low-calorie, low-carb diets, "crash diets", alcohol, periods of starvation. Low fiber diets are implicated in constipation problems.
Infections (because of the stress it puts on the body's immune system) and sunlight can set off an attack for any of the porphyrias affecting the skin, and sunscreens MUST be titanium dioxide and/or zinc oxide only - the oxybenzone chemical family will NOT work.
What is the prognosis of the porphyrias?
Once properly diagnosed and treated, prognosis is excellent and the patient can expect to live relatively normally.
If untreated and undiagnosed, however, the lifespan is typically greatly shortened due to the long term toxic effects of excess porphyrins on the body's organs (including the heart!) and tissues.
How are they treated?
The patient may be advised to:
- Stop any aggravating medications, alcohol, and other chemicals
- Add Fluids and glucose to boost carbohydrate levels (carbs limit the production of porphyrins)
- Switch to a high carbohydrate diet
- Sun avoidance for any porphyria type affecting the skin
- Avoid iron deficiency (iron deficiency can compromise heme creation and set off an attack)
- Peel any fruit that has been sprayed (insecticides can trigger attacks)
- Peel and/or thoroughly rinse any vegetable that has been sprayed (same reason)
- High glucose/dextrose beverages (sports drinks - but read labels, you don't want fructose)
- Keep glucose tablets on hand; during an attack extra glucose hourly may help minimize symptoms
Medical professionals will need to:
- Monitor for electrolyte issues; supplement if necessary (typically sodium and magnesium)
- Treat respiratory issues if/when they happen
- Monitor, identify and treat heart issues
- Treat pain - may need multiple methods of pain control for serious relief
- Panhematin as needed (Hematin or heme arginate infusion have been used in the past, but are considered obselete by some)
- Phlebotomy for some forms of porphyria to reduce porphyrin buildup
- Use IV glucose as needed (for carbs to reduce the severity of an attack)
What does this have to do with real vampires?
Nothing, actually. Many real vampires have photosensitivity, the same as the cutaneous forms of porphyria. However, that's where the similarity ends - porphyria is caused by the buildup of porphyrins in the liver and/or the skin. Real vampirism by itself does not have a porphyrin problem.
- Drugs & Porphyria
- Porphyria - General
- Porphyria - Medical
- Clinical Chemistry 20: 1438-1440, 1974 (PDF)
- eMedicine: Porphyria Overview
- eMedicine: Porphyria, Acute Intermittent
- eMedicine: Porphyria, ALA Dehydratase
- eMedicine: Porphyria, Congenital Erythropoietic
- eMedicine: Porphyria Cutanea Tarda
- eMedicine: Porphyria, Hereditary Coproporphyria
- eMedicine: Porphyria, Variegate
- eMedicine: Pseudoporphyria
- Genetic Home Reference: Porphyria
- Medscape: Chart of Heme Production Process (image)
- Merck Manual: Porphyria Overview