Types of porphyria: acute, cutaneous, and more

Porphyria is the name given to a group of metabolic disorders related to abnormal enzyme activity during the production of heme, an important component in numerous substances the body depends on to function properly. Different types of porphyrias cause different symptoms. Some affect the nervous system, some affect the skin, and some affect both.

Types of porphyria

There are eight enzymes needed for the body to synthesize heme. In simplified terms, each acts as a stage in the heme-making process. Porphyrins are natural chemical compounds that result at each stage. When the body is deficient in one of these enzymes, heme production bottlenecks, and it is stuck with porphyrins it cannot continue converting into heme. This results in a buildup of porphyrins in the body, which can disrupt normal functioning and cause a variety of symptoms.

The different types of porphyria are named based on the specific enzyme that is deficient. Different types of porphyria can also be placed into broader categories.

Acute porphyria

A simple method for classifying porphyrias is to label them acute or cutaneous. In medical terms, “acute” describes symptoms that appear suddenly and progress quickly. Acute porphyrias typically affect nerves—either peripheral nerves near the surface of the body, or visceral nerves in the organs. Acute porphyrias can cause a variety of symptoms:

• Neurological symptoms, which can include pain (in the back, chest, and legs), tingling and numbness in the hands and feet, muscle weakness or paralysis, rapid heartbeat, difficulty breathing, and seizures.
• Mental changes, such as confusion, anxiety, paranoia, and hallucinations.
• Gastrointestinal symptoms, such as nausea and vomiting, constipation or diarrhea, and abdominal pain.
• Problems urinating, such as difficulty emptying the bladder, and urine that is red or brown in color.

There are four types of porphyria that are categorized as acute:

• Acute intermittent porphyria
• Hereditary coproporphyria
• Variegate porphyria
• Delta-aminolevulinate-dehydratase deficiency porphyria

Cutaneous porphyria

Cutaneous porphyrias cause skin symptoms (“cutaneous” being the clinical term for something that relates to the skin). With this type of porphyria, porphyrins accumulate in the skin and become unstable when exposed to sunlight. As a result, the skin can become blistered, discolored, swollen, and itchy. Two types of acute porphyria—variegate porphyria and hereditary coproporphyria—also cause cutaneous symptoms.

There are four types of cutaneous porphyria:

• Congenital erythropoietic porphyria
• Porphyria cutanea tarda
• Hepatoerythropoietic porphyria
• Erythropoietic protoporphyria

Erythropoietic and hepatic porphyrias

Heme is produced in the bone marrow and the liver, and porphyrias can also be categorized based on the location in the body that is producing an excess amount of porphyrins. These include hepatic types, for porphyrins produced in the liver, and erythropoietic types, for porphyrins that are produced by the bone marrow.

Secondary porphyria

To diagnose porphyria, a healthcare provider (HCP) will order diagnostic tests that look for levels of porphyrins in the blood, urine, and/or stool. Trace amounts of porphyrins are normal, but high levels indicate porphyria. An HCP may also recommend DNA testing to look for genetic mutations that are known to cause porphyrias.

In some cases, high levels of porphyrins in the urine are the result of something other than porphyria. This can be a health condition, such as blood disorders or liver disorders, or exposure to toxic substances, such as lead, alcohol, or benzene (an industrial chemical). This is called secondary porphyria.

If you or a loved one has any variety of porphyria, it is important to work with your HCP to get an accurate diagnosis and treatment. There are effective treatments available for porphyrias, and the disorders can often be controlled with medications, lifestyle changes, and steps to avoid triggers.