Common Misdiagnoses of Porphyria

By Cynthia G. Chase
Porphyria is not a single disease but a group of eight rare, mostly inherited enzyme deficiency disorders which affect heme bio-synthesis. Heme is a component of hemoglobin. Genetic defects in any one of the eight separate enzymes responsible for heme production can cause a buildup of porphyrins in the body. Although porphyrins are natural compounds which aid in the creation of red blood cells, an excessive buildup of porphyrins can be toxic and can lead to acute or cutaneous porphyria. Symptoms may include photodermatitis, abdominal cramping, changes in personality and neurological dysfunction.

Types of Porphyria Disorders

The American Porphyria Network lists eight separate porphyria disorders. Four of these are classified as "acute" disorders. They disturb the central nervous system and can cause sudden and severe attacks of stomach pain, heart palpitations and changes in blood pressure. The remaining varieties affect the skin and are known as "cutaneous" porphyrias.

Acute Intermittent Porphyria, or "AIP," is a more commonly diagnosed variety of acute porphyria. The inherited disease usually manifests itself after puberty. An attack can last for hours or several days and may require hospitalization. Gastrointestinal complaints include nausea, vomiting, severe stomach pain and constipation. The autonomic nervous system is disrupted during an acute attack. This can lead to heart arrhythmia, elevated blood pressure, shock, muscle weakness, tremor and seizures. Hallucinations, confusion or paranoia may occur.

According to the Mayo Clinic, Porphyria Cutanea Tarda, or "PCT," affects "about 80 percent of patients with porphyria. It is the most common non-acute porphyria and by far the most common porphyria." Symptoms of PCT include sensitivity to sun, rashes, swelling of the skin, blisters, hyperpigmentation and the presence of red or purplish pigment in the urine. Dermatologists recommend that patients with PCT wear sunblock and protective clothing during the day.

Errors in Diagnosis

It can be difficult to diagnosis porphyria. The disorder is rare and occurs in approximately 1 in 50,000 people worldwide. Symptoms of acute porphyria can resemble other disorders or diseases, such as Guillain-Barre syndrome, lead poisoning and appendicitis. The early stages of Guillain-Barre syndrome is characterized by a tingling of the feet or legs, muscle weakness and loss of motor control. These symptoms are similar to the symptoms and signs of AIP. The pains associated with appendicitis, such as nausea, vomiting and sharp stomach pain, are also common in patients with Acute Intermittent Porphyria. A porphyrin precursor called aminolevulinic acid, or "ALA," is excreted in large amounts in the kidneys of individuals with chronic lead poisoning and in those who have AIP. The two maladies share many symptoms, including tingling in the extremities, muscle weakness, abdominal pain and neurological decline.

Proper Diagnosis

An individual who suspects he or she is ill with porphyria can reduce the risk of delayed or missed diagnosis by consulting with a porphyria specialist. The patient will be asked to give urine, blood and stool samples to test for elevated levels of porphyrons and enzyme abnormalities. The specialist will most likely work in tandem with a laboratory that is skilled in porphyria biochemical testing.

DNA testing is used to confirm a diagnosis of porphyria. According to the American Porphyria Association, "Each porphyria is caused by a mutation in the DNA sequence of a specific gene." Symptoms differ in all eight varieties of porphyria. Treatment is available for each disorder. There is no cure for this disease.

Obtaining Legal Help

If you you have porphyria and have suffered from a delayed or missed diagnosis due to medical negligence or error, it is best to contact a qualified medical malpractice attorney to assist you with your case.