Porphyria

Updated: 2020-06-03

Overview

Porphyria (por-FEAR-e-uh) refers to a group of disorders that result from a buildup of natural chemicals that produce porphyrin in your body. Porphyrins are essential for the function of hemoglobin — a protein in your red blood cells that links to porphyrin, binds iron, and carries oxygen to your organs and tissues. High levels of porphyrins can cause significant problems.

There are two general categories of porphyria: acute, which mainly affects the nervous system, and cutaneous, which mainly affects the skin. Some types of porphyria have both nervous system symptoms and skin symptoms.

Signs and symptoms of porphyria vary, depending on the specific type and severity. Porphyria is usually inherited — one or both parents pass along an abnormal gene to their child.

Although porphyria can't be cured, certain lifestyle changes to avoid triggering symptoms may help you manage it. Treatment for symptoms depends on the type of porphyria you have.

Symptoms

Symptoms of porphyria can vary widely in severity, by type and among individuals. Some people with the gene mutations that cause porphyria never have any symptoms.

Acute porphyrias

Acute porphyrias include forms of the disease that typically cause nervous system symptoms, which appear quickly and can be severe. Symptoms may last days to weeks and usually improve slowly after the attack. Acute intermittent porphyria is the common form of acute porphyria.

Signs and symptoms of acute porphyria may include:

• Severe abdominal pain
• Pain in your chest, legs or back
• Constipation or diarrhea
• Nausea and vomiting
• Muscle pain, tingling, numbness, weakness or paralysis
• Red or brown urine
• Mental changes, such as anxiety, confusion, hallucinations, disorientation or paranoia
• Breathing problems
• Urination problems
• Rapid or irregular heartbeats you can feel (palpitations)
• High blood pressure
• Seizures

Cutaneous porphyrias

Cutaneous porphyrias include forms of the disease that cause skin symptoms as a result of sensitivity to sunlight, but these forms don't usually affect your nervous system. Porphyria cutanea tarda (PCT) is the most common type of all the porphyrias.

As a result of sun exposure, you may experience:

• Sensitivity to the sun and sometimes artificial light, causing burning pain
• Sudden painful skin redness (erythema) and swelling (edema
• Blisters on exposed skin, usually the hands, arms and face
• Fragile thin skin with changes in skin color (pigment)
• Itching
• Excessive hair growth in affected areas
• Red or brown urine

When to see a doctor

Many signs and symptoms of porphyria are similar to those of other, more common conditions. This can make it difficult to know if you're having an attack of porphyria. If you have any of the above symptoms, seek medical attention.

Causes

Autosomal dominant inheritance pattern

Autosomal dominant inheritance pattern

In an autosomal dominant disorder, the altered gene is a dominant gene located on one of the nonsex chromosomes (autosomes). You need only one altered gene to be affected by this type of disorder. A person with an autosomal dominant disorder — in this case, the father — has a 50% chance of having an affected child with one altered gene (dominant gene) and a 50% chance of having an unaffected child with two typical genes (recessive genes).

Autosomal recessive inheritance pattern

Autosomal recessive inheritance pattern

To have an autosomal recessive disorder, you inherit two changed genes, sometimes called mutations. You get one from each parent. Their health is rarely affected because they have only one changed gene. Two carriers have a 25% chance of having an unaffected child with two unaffected genes (left). They have a 50% chance of having an unaffected child who also is a carrier (middle). They have a 25% chance of having an affected child with two changed genes (right).

All types of porphyria involve a problem in the production of heme. Heme is a component of hemoglobin, the protein in red blood cells that carries oxygen from your lungs to all parts of your body. Heme production, which occurs in the bone marrow and liver, involves eight different enzymes — a shortage (deficiency) of a specific enzyme determines the type of porphyria.

In cutaneous porphyria, the porphyrins build up in the skin, and when exposed to sunlight, cause symptoms. In acute porphyrias, the buildup damages the nervous system.

Genetic forms

Most forms of porphyria are inherited. Porphyria can occur if you inherit:

• A defective gene from one of your parents (autosomal dominant pattern)
• Defective genes from both parents (autosomal recessive pattern)

Just because you inherit a gene or genes that can cause porphyria doesn't mean that you'll have signs and symptoms. You might have what's called latent porphyria, and never have symptoms. This is the case for most carriers of the abnormal genes.

Acquired forms

Porphyria cutanea tarda (PCT) typically is acquired rather than inherited, although the enzyme deficiency may be inherited. Certain triggers that impact enzyme production — such as too much iron in the body, liver disease, estrogen medication, smoking or excessive alcohol use — can cause symptoms.

Risk factors

In addition to genetic risks, environmental factors may trigger the development of signs and symptoms in porphyria. When exposed to the trigger, your body's demand for heme production increases. This overwhelms the deficient enzyme, setting in motion a process that causes a buildup of porphyrins.

Examples of triggers include:

• Exposure to sunlight
• Certain medications, including hormone drugs
• Recreational drugs
• Dieting or fasting
• Smoking
• Physical stress, such as infections or other illnesses
• Emotional stress
• Alcohol use
• Menstrual hormones ― acute porphyria attacks are rare before puberty and after menopause in women

Complications

Possible complications depend on the form of porphyria:

• Acute porphyrias can be life-threatening if an attack isn't promptly treated. During an attack, you may experience dehydration, breathing problems, seizures and high blood pressure. Episodes often require hospitalization for treatment. Long-term complications with recurrent acute attacks may include chronic pain, chronic kidney failure and liver damage.
• Cutaneous porphyrias can result in permanent skin damage. Also, the skin blisters can become infected. When your skin heals after cutaneous porphyria, it may have an abnormal appearance and coloring, be fragile, or leave scars.

Prevention

Although there's no way to prevent porphyria, if you have the disease, avoid triggers to help prevent symptoms.

Because porphyria is usually an inherited disorder, your siblings and other family members may want to consider genetic testing to determine if they have the disease, and get genetic counseling if needed.

Diagnosis

Many signs and symptoms of porphyria are similar to those of other more common diseases. Also, because porphyria is rare, it can be more difficult to diagnose.

Lab tests are required to make a definitive diagnosis of porphyria and to determine which form of the disease you have. Different tests are performed depending on the type of porphyria your doctor suspects. Tests include a combination of blood, urine or stool testing.

More tests may be needed to confirm the type of porphyria you have. Genetic testing and counseling may be recommended in the family of a person with porphyria.

Treatment

Treatment depends on the type of porphyria you have and the severity of symptoms. Treatment includes identifying and avoiding symptom triggers and then relieving symptoms when they occur.

Avoiding triggers

Avoiding triggers may include:

• Not using medications known to trigger acute attacks. Ask your doctor for a list of safe and unsafe drugs.
• Not using alcohol or recreational drugs.
• Avoiding fasting and dieting that involves severe calorie restriction.
• Not smoking.
• Taking certain hormones to prevent premenstrual attacks.
• Minimizing sun exposure. When you're outdoors, wear protective clothing, and use an opaque blocking sunscreen, such as one with zinc oxide. When indoors, use window filters.
• Treating infections and other illnesses promptly.
• Taking steps to reduce emotional stress.

Acute porphyrias

Treatment of acute porphyria attacks focuses on providing rapid treatment of symptoms and preventing complications. Treatment may include:

• Injections of hemin, a medication that is a form of heme, to limit the body's production of porphyrins
• Intravenous sugar (glucose), or sugar taken by mouth, if able, to maintain an adequate intake of carbohydrates
• Hospitalization for treatment of symptoms, such as severe pain, vomiting, dehydration or problems breathing

In 2019, the FDA approved givosiran (Givlaari) as a monthly injection for adults with acute hepatic porphyria to reduce the number of porphyria attacks. But it’s important to discuss safety information and potential serious side effects with your doctor. These include but are not limited to nausea, liver and kidney toxicity, and a small risk of anaphylaxis.

Cutaneous porphyrias

Treatment of cutaneous porphyrias focuses on reducing exposure to triggers such as sunlight and reducing the amount of porphyrins in your body to help eliminate your symptoms. This may include:

• Periodically drawing blood (phlebotomy) to reduce the iron in your body, which decreases porphyrins.
• Taking a drug used to treat malaria — hydroxychloroquine (Plaquenil) or, less often, chloroquine (Aralen) — to absorb excess porphyrins and help your body get rid of them more quickly than usual. These medications are generally used only in people who can't tolerate a phlebotomy.
• A dietary supplement to replace vitamin D deficiency caused by avoidance of sunlight.

Lifestyle and home remedies

If you have porphyria:

• Learn what could trigger symptoms. Talk to your doctor about the type of porphyria you have and become familiar with possible symptom triggers and ways to avoid them.
• Inform your health care providers. Tell all your health care providers that you have porphyria. This is particularly important because sometimes treatments, medications or surgery can trigger porphyria symptoms.
• Wear a medical alert bracelet or necklace. Have information about your condition inscribed on a medical alert bracelet or necklace, and always wear it.

Coping and support

Porphyria is considered a chronic illness, as the underlying cause can't be cured. However, porphyria usually can be managed by treatment and lifestyle changes so that you can live a full and healthy life.

Preparing for an appointment

If you have signs and symptoms of porphyria, you're likely to start by seeing your primary care provider. However, because porphyria can be difficult to diagnose, you may be referred to a doctor who specializes in blood disorders (hematologist).

Here's some information to help you get ready, and what to expect from your doctor.

What you can do

Before your appointment, make a list of:

• Any symptoms you're experiencing, including any that may seem unrelated to the reason for your appointment
• Key personal information, including any major stresses or recent life changes
• All medications, vitamins, herbs or other supplements that you're taking, including dosages
• Questions to ask your doctor

Questions to ask your doctor may include:

• What's the most likely cause of my symptoms?
• What are other possible causes?
• What kinds of tests do I need?
• What's the best course of action?
• What are the alternatives to the primary approach that you're suggesting?
• I have another health condition. How can I best manage these together?
• Are there any precautions or restrictions I should follow?
• Do I need genetic testing? If so, should my family members be screened?
• Are there any brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you several questions. Be ready to answer them to spend time on areas you want to focus on. Some questions your doctor may ask include:

• When did you first begin experiencing symptoms?
• Have your symptoms been continuous or occasional?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?
• Do any family members have similar symptoms?