Rare Disease Report

Porphyria Why Does It Take 10-15 Years to be Diagnosed?

APRIL 25, 2017
James Radke
Imagine a young female comes into the ER with abdominal pain and constipation.

A good ER doctor would suspect a poor diet, ovary cysts, endometrosis, or any number of other common problems to explain the pain, and they would conduct the appropriate tests to confirm or deny those common conditions.
 
Unfortunately, a rare disease called porphyria, may be the problem. And because it is a rare disease, it occurs in young women during their menstrual cycle, it is generally a pain that subsides over time, and it is also associated with binge drinking, stress, and poor diet, the disease is generally not suspected.
 
A young female can have that condition for up to 10 or 15 years before being properly diagnosed. 
 
To help raise awareness of this condition and to commemorate National Porphyria Awareness Week (April 22 - 29, 2017), we talked with Herbert L. Bonkovsky, M.D., Professor of Medicine at  Wake Forest Baptist Health in Winston-Salem, NC, and a leading clinical researcher about this rare and often misdiagnosed condition.
 
Porphyria is a group of disorders that result from a buildup of natural chemicals that produce porphyrin in your body. Porphyrins are vital for the role 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.
 
The most common form of the rare disease is acute intermittent porphyria. It is characterized by a deficiency of porphobilinogen deaminase and as the name implies, the symptoms involve acute painful attacks.
 
The most common symptom is a severe and poorly localized abdominal pain. These attacks usually occur in females, aged 20-55 years of age, and they seem to be associated with the menstrual cycle, stress, as well as extreme dieting and alcohol intake.

10-15 years to get diagnosed

It can take up to 10 to 15 years for a person with acute intermittent porphyria to be properly diagnosed. The reasons for the delay in diagnosis are numerous. First and foremost is that the gastrointestinal pains may not be recognized as signs of porphyria but rather other more common ailments (poor diet, endometriosis, gallstones, ovary cysts, etc).
 
According to Dr. Bonkovsky, porphyria should be suspected more readily but it is generally not. A typical case is a young woman who returns emergency room with severe pain who in previous visits, had shown that her scans revealed no clear explanation for her pain. Dr. Bonkovsky believes porphyria should be suspected at that time and a simple urine test to measure porphobilinogen (PBG) would provide the evidence needed to suspect porphyria.
 
But according to Dr. Bonkovsky, the nature of the attacks plus the time delay for getting the urine test results back is another confounding factor. Dr. Bonkovsky noted that the 5-10 days delay in getting results back means the patient is no longer in the emergency department and is actually feeling normal again. As a result, “follow-up is far from good, unfortunately.”

Treatments available

Once a person is diagnosed, the main treatment is to prevent attacks via diet and lifestyle. It is recommended that women avoid alcohol and extreme diets, and to not take estrogens/progesterone.
 
During an acute attack, Dr. Bonkovsky said analgesics can help and in some cases, oral or IV glucose may be used. During an attack, nausea and pain can make it difficult for patients to stick to a steady diet but not eating can augment to acute symptoms.
 
The more specific treatment is intravenous heme (Panhematin) which is effective in reducing the intensity and duration of an attack.
 
Dr. Bonkovsky said there is a tremendous need for other treatments for porphyria and he is hopeful that a new RNAi drug in development by Alnylam may prove to be effective. Preliminary results from a phase 1 study are promising.
 
 
 


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