Porphyria

DEFINITION

Porphyria (poor-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 tissue. High levels of porphyrins can cause significant problems.

Porphyria mainly affects your nervous system, skin and other organs. The signs and symptoms of porphyria can vary, depending on the specific type and severity. Porphyria is usually inherited — one or both parents pass along an abnormal gene to their child. But in some types of porphyria, environmental factors may trigger the development of symptoms.

Treatment depends on the type of porphyria you have. Although porphyria usually can’t be cured, certain lifestyle changes may help you manage it.

CAUSES

Porphyria is most often an inherited mutation in one of the genes involved in heme production, although environmental factors can trigger symptoms in some cases.

Heme is a major component of hemoglobin, the protein in red blood cells that carries oxygen from your lungs to all parts of your body. Heme also plays a role in breaking down chemicals so they can be removed from your body. Heme is made mainly in the bone marrow and liver through the production of porphyrin and linkage with iron.

Eight different enzymes add and convert natural, smaller building blocks into porphyrin, which becomes heme with the addition of iron. Deficiency of a specific enzyme that’s involved in the body’s process for making heme can result in the buildup of porphyrins, causing symptoms. Each type of porphyria is due to the deficiency of a different enzyme.

Genetics

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 have inherited 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.

SYMPTOMS

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, and others have mainly one or the other.

Acute porphyrias

Acute porphyrias include forms of the disease that typically cause nervous system symptoms, which appear quickly and can be life-threatening. Acute porphyria attacks are rare before puberty and after menopause in women. Symptoms may last one to two weeks and usually improve slowly after the attack.

Possible signs and symptoms of acute porphyria include:

• Severe abdominal pain
• Swelling of the abdomen (abdominal distention)
• Pain in your chest, legs or back
• Constipation or diarrhea
• Vomiting
• Insomnia
• Heartbeat you can feel (palpitations)
• High blood pressure
• Anxiety or restlessness
• Seizures
• Mental changes, such as confusion, hallucinations, disorientation or paranoia
• Breathing problems
• Muscle pain, tingling, numbness, weakness or paralysis
• Red or brown urine

Cutaneous porphyrias

Cutaneous porphyrias include forms of the disease that cause skin symptoms as a result of oversensitivity to sunlight, but these forms don’t usually affect your nervous system. Attacks may last for several days. With some forms, signs and symptoms may start during infancy or childhood.

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 that take weeks to heal
• Itching
• Fragile skin
• Scars or skin color changes from healing blisters
• Increased hair growth
• 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. Any of the following symptoms should prompt you to seek immediate medical attention:

• Severe abdominal pain, but sometimes pain in your chest, legs or back, accompanied by constipation, vomiting and sometimes diarrhea
• Sensitivity to the sun and sometimes artificial light, causing burning pain and sudden painful skin blistering, redness (erythema) and swelling (edema)
• Red or brown urine