Porphyria is a group of rare metabolic disorders caused by a build-up of porphyrins in the body. These porphyrins are needed to manufacture haem which is part of haemoglobin. This protein found in red blood cells aids in oxygen transportation around the body, supplying tissues and organs with oxygenated blood.
A number of enzymes are required to complete the process of changing porphyrins into haem. If there is a deficiency in any of the required enzymes, then this results in the build-up of porphyrins. Over time, this continuous increase in porphyrin levels can create major problems, especially in the nervous system and skin.
There are two main types of porphyria, and these are acute porphyria, which mainly affects the nervous system with a rapid onset of symptoms, whilst cutaneous porphyrias mainly causes skin problems. Symptoms and severity are highly dependent on the type of porphyria inherited. However, there is no cure for any of the forms of this disease.
Acute porphyria can cause skin and nervous system symptoms in sufferers. Symptoms can last for up to a few weeks at a time. The most common form of acute porphyria is called acute intermittent porphyria (AIP). With AIP, symptoms can come and go, and when symptoms do appear, they are sometimes described as acute porphyria attacks.
The main symptoms are digestive problems such as nausea and vomiting. Bowel problems such as constipation can be present too. Severe body pain is also extremely common, and this can affect the chest, stomach, back, and legs. The pain experienced in the legs can be severe enough to interfere with walking and general mobility. In severe attacks, numbness, paralysis, and weakness can also be experienced.
Mental health can also be affected by panic and anxiety attacks, along with mental confusion and even hallucinations. Seizures, high blood pressure, irregular heartbeat, and red or brown urine are other possible symptoms.
Those with cutaneous porphyrias are most likely to experience skin symptoms. Mostly the skin symptoms that appear are a result of skin exposure to direct sunlight. Sensitivity to the sun can be extreme and cause burning and blistering of the skin. The skin can also swell and cause the sufferer constant pain and discomfort.
All forms of this condition revolve around a problem-making haem, the precursor to haemoglobin. This is manufactured in the bone marrow and liver. The process of turning porphyrins into haem involves eight different enzymes.
A shortage of any of these enzymes creates a build-up of porphyrins which in turn leads to the development of porphyria. The type of porphyria one gets depends on which of the enzymes is affected.
Most forms of porphyria are caused by gene mutations passed down to children either in an autosomal dominant pattern, where the mutation comes from one parent, or an autosomal recessive pattern, which is when mutated genes are inherited from each parent.
Apart from the genetic factors for developing this condition, environmental risk factors, such as sunlight, can also contribute to symptoms of sufferers, especially if cutaneous porphyria is present.
Lab tests are the best way to diagnose and determine which form of porphyria is present. A combination of stool, urine, and blood tests should be performed to measure enzyme activity and porphyrin levels in the body.
If there are certain triggers apart from sunlight, such as medicines or smoking, that flare symptoms, then these should be avoided. If infections do the same, then prompt treatment of them should be sought.
Symptoms can be treated with certain drugs, such as forms of haem that reduce the body’s need to produce its own. Oral and intravenous glucose can help maintain energy intake.
To prevent this condition, potential carriers of the faulty genes can be screened before considering having children.