Porphyria is a group of disorders that are caused due to a buildup of natural chemicals with links to a red blood cell protein called Porphyrin.
You will find a lot of research-focused scientific information on Porphyria available on the internet (1). However, this article is written with the general public in mind.
You won’t need to have a degree in Cell Biology to understand the facts about this rare disorder presented in this article.
What Is Porphyria?
Porphyria is a set of eight disorders that mainly affect the nervous system and skin (2).
These disorders also cause many adverse effects, including abdominal pain and paralysis.
A key point to remember about Porphyria is that these disorders are usually inherited from generation to generation (3). So, if someone is diagnosed with one of these disorders, the chances are that one of their parents has the same disorder.
What Happens When You Have These Disorders?
If you had Porphyria, the cells in your body fail to turn porphyrins (and porphyrin precursors) into heme (4).
This Heme is the stuff that gives your blood its red colour and is made in your liver and bone marrow. Its job is to carry oxygen from the lungs and deliver it throughout the body. It also helps liver cells function properly.
The Heme biosynthetic pathway is the process in which porphyrins are processed into producing heme. This process requires eight key enzymes to complete this conversion and a deficiency in one or more of these enzymes can cause a buildup of Porphyrins.
Types Of Porphyria:
There are two main types of Porphyria, Acute and Non-acute (cutaneous) Porphyria.
Acute Porphyria includes:
- Acute intermittent porphyria (AIP)
- Variegate porphyria (VP)
- Aminolevulinic acid dehydratase deficiency porphyria (ALAD)
- Hereditary coproporphyria (HCP)
Cutaneous Porphyria includes:
- X-linked dominant protoporphyria (XLDPP)
- Congenital erythropoietic porphyria (CEP)
- Porphyria cutanea tarda(PCT)
- Erythropoietic protoporphyria (EPP)
Acute Porphyria affects the nervous system and can be quite severe, often requiring treatments in the hospital and weeks of recovery.
On the other hand, Cutaneous Porphyria affects the skin, often by altering the skin’s sensitivity to sunlight.
A key difference between the two is that Acute Porphyria disorders are often episodic while Cutaneous Porphyria disorders are usually permanent in nature.
Acute Porphyria Symptoms:
- Severe abdominal pain
- High blood pressure
- Red/brown urine
- Numbness, tingling, weakness muscle pain, or paralysis
- Difficulty in breathing
- Pain in the chest, back, or legs
- Trouble peeing
- Anxiety, disorientation, confusion, hallucinations, or paranoia (Mental Illnesses)
- Nausea and vomiting
- Diarrhoea or constipation
Cutaneous Porphyria Symptoms:
- Fragile skin that bruises easily
- Increased sensitivity to the sun
- Blisters on skin exposed to the sun (caused Porphyria vampire myths)
- Painful skin redness and swelling
- Excessive hair growth in the exposed areas (caused werewolf myths)
- Change in pigment colour of the skin
- Burning pain when exposed to sun or artificial light
- Red/brown urine
The majority of Porphyria disorders are inherited from one or both parents, all of which have been identified. The defective gene is often unnoticed until the Porphyria is triggered.
Common Triggers For All Porphyria Disorders:
- Being exposed to sunlight
- Alcohol consumption
- Smoking cigarettes
- Some medications or hormones
The only Porphyria that can be acquired and not inherited is Porphyria cutanea tarda.
Porphyria Cutanea Tarda Can Be Triggered By:
- Having an excessive Iron intake
- Drinking alcohol
- Having Iron overload disease
- Using estrogen products/drugs
- Having HIV
- Suffering from Chronic hepatitis C
What Drugs May Cause Porphyria?
- Antipsychotics like risperidone and ziprasidone
- Antifungals with high absorption rate (fluconazole, ketoconazole, griseofulvin, and voriconazole)
- Some cancer drugs like bexarotene, estramustine, megestrol, letrozole, and mitomycin.
- Antidepressants like phenelzine, imipramine, and trazodone
- Some painkillers like ketorolac, metamizole, dextropropoxyphene, and pentazocine
- Rifapentine, rifampicin, and other antibiotics
- Some antiretroviral medications like indinavir, ritonavir, saquinavir, and nevirapine
- Some anticonvulsants like ethosuximide, carbamazepine, phenytoin, valproate, and topiramate.
- Ergot derivatives
How Is Porphyria Diagnosed?
Many doctors find it challenging to test for Porphyria because the symptoms are very similar to other illnesses.
That said, Porphyria testing using blood, urine, or stool is the first step in the diagnosis.
Additional testing includes taking a DNA test using the blood sample to find the gene mutations that may be the cause of your Porphyria.
According to some experts, the ideal time to do the tests is when you have an episode. This is because it’s around that time your body should have high levels of Porphyrins or Porphyrin precursors.
Your family members may also be asked to do a DNA test to find if they too have the gene mutations in question.
The particular treatment that you are prescribed will depend on the type of Porphyria you have. The treatment usually includes avoiding triggers and relieving symptoms (5).
Acute Porphyria Treatment:
- Treating symptoms like problems breathing, severe pain, dehydration, or vomiting
- Hemin injections to boost Heme levels and limit Porphyrins production
- Maintaining adequate carbohydrate levels with intravenous glucose or sugar taken orally
Cutaneous Porphyria Treatment:
- Reducing exposure to triggers
- Drawing blood periodically to reduce iron and porphyrins levels
- Taking anti-malaria drugs like Plaquenil and Aralen to absorb excess porphyrins
- Vitamin D supplements to combat the deficiency that’s caused by avoiding sunlight
While there are treatments for the symptoms of Porphyria, there is no known cure. So, sufferers of Porphyria can only reduce their exposure to the triggers like sunlight regularly.
This is difficult for people as it restricts many freedoms and causes complications as well. The worst part is that having children also means that there is a risk of babies having the same disease.
However, the National Institutes of Health (NIH) conduct clinical trials that can help prevent, detect, and treat such diseases and disorders (6).
So, there is a chance that sometime in the future we will be able to find a cure for Porphyria.