On Thursday, we challenged Well readers to figure out the diagnosis for a 30-year-old man with a two-week history of severe abdominal pain.
More than 600 readers wrote in with some very thoughtful assessments of this patient’s problem.
The correct diagnosis is…
Acute Intermittent Porphyria
The first person to figure it out was Dr. Hilary Seligman, from the University of California, San Francisco. She says that during her medical school years at Baylor in Houston, she learned that there were five causes of severe abdominal pain that should never be overlooked. Porphyria was one of them. And she always thinks of it when she sees a patient with that kind of pain.
Acute intermittent porphyria, or A.I.P., is one of a group of rare disorders, passed down through families, in which an important part of hemoglobin called heme is not made properly. Patients with A.I.P. suffer episodes of severe abdominal pain, constipation, hypertension and tachycardia that usually last several days. It can also be associated with nerve problems — numbness, tingling, even weakness — as well as psychiatric disorders. In between symptomatic episodes, patients can be completely normal.
This genetic disease is rare. In the United States, fewer than five people in 100,000 will have it. But the disease is made even more rare because most of the people who have inherited the genetic abnormality responsible for it will never have symptoms. The symptoms are usually triggered by medications or other environmental stimulation.
How the Diagnosis Was Made:
Dr. Ron Palmon, the gastroenterologist who examined the patient when he was first admitted to Mount Sinai, was called to see the patient again when he returned to the hospital. Dr. Palmon focused first on the patient’s history and physical exam, and then turned to the patient’s medical records to see if there were any clues hidden there. There were.
While Dr. Palmon wasn’t surprised by most of the information there, he made one important discovery. The day after the patient had his exploratory surgery, the surgeon had ordered a urine porphobilinogen, which is a test for porphyria. The test result didn’t come back until days after the patient had gone home, and for this reason, it had not been noted by the doctor who ordered it, and the patient had not been told.
A Definitive Diagnosis:
As a gastroenterologist, Dr. Palmon was familiar with porphyria, but he wasn’t sure how reliable the test for it was. This patient’s PBG was very high — he had 40 times the normal amount of this biological chemical in his urine. But did that mean he had porphyria? Dr. Palmon wasn’t certain, so he read up on it. He learned that the urine test that was ordered requires follow-up testing to confirm the finding and to determine exactly which type of porphyria it represents.
Dr. Palmon knew that with a disease this unusual, a positive test result is more likely to be an error than it is to be a true indicator of one of the porphyrias. So he sent off the confirmatory test. And he sent off tests for some of the other diseases that can cause a false positive in the PBG test.
The patient and his wife were excited that Dr. Palmon might be able to identify the cause of this terrible pain. He and his wife did a Web search on the term “A.I.P.” The more they read, the more certain they were that this was the right diagnosis. In A.I.P., painful episodes are often triggered by fasting or low-carb diets. This patient had been on a low-carb diet in the weeks before his pain started. A.I.P. often causes high blood pressure and a rapid heart rate — at least during the painful episodes. This patient had also experienced a rapid heart rate and very high blood pressure — something he’d never had before.
Over the course of the next several days, the patient’s pain eased. He was switched to pain medicines he could take by mouth and was discharged. The results of the second round of tests for porphyria didn’t come back for days. When they finally did, the diagnosis of acute intermittent porphyria was confirmed.
Patient who have A.I.P. can avoid these painful episodes by trying to avoid triggers — in this patient’s case, a low-carb diet. If a patient gets one of these attacks despite this effort, a medication called hematin can be given to bring a rapid resolution of pain.
A Different Kind of Inheritance:
As soon as he saw the result, Dr. Palmon called to let the patient and his wife know, and he referred them to the Porphyria Clinic at Mount Sinai Hospital. DNA testing confirmed that the patient carried the genetic abnormality behind the disease.
The patient’s father was tested, and he, too, carried the genetic abnormality. The older man never knew, however, because he was one of the many who have the gene but never develop any symptoms of the disease. Because the patient’s children have a 50-50 chance of inheriting the trait, the patient and his wife are discussing when and whether to have their two boys tested.
A Problem in the System:
In this case, the patient benefited from a fairly rapid diagnosis of his porphyria. Although those weeks of pain may have seemed like years to the patient, the average time to diagnosis for most patients with this disease is counted in years rather than weeks, according to Desiree Lyon Howe, the executive director of the American Porphyria Foundation. When the patient and his wife met others with porphyria at the Mount Sinai clinic, they were amazed and horrified to hear the common story of years of painful episodes before a diagnosis was made.
Nevertheless, this diagnosis was almost missed. If the patient hadn’t gone back to Mount Sinai when the pain returned, it is very unlikely that he would have found out about his positive test. Who knows how long it might have taken for him to get the right diagnosis?
Dr. Palmon spoke with the surgeon who ordered the test. It is this doctor’s practice to check for porphyria after a “negative” exploratory surgery for severe abdominal pain. But these results didn’t come in until the patient had gone home. In this hospital and others, these test results don’t go to the doctor who ordered them, but are placed in the patient’s chart. Once a patient goes home, that chart is often not even looked at unless the patient comes back to the hospital. And sometimes, not even then.
Some hospitals have developed systems to make certain that postdischarge test results do not languish in some unchecked chart. At the Brigham and Women’s Hospital in Boston, Dr. Anuj Dalal, a hospitalist, started to worry about these postdischarge results. A study done at his institution showed that on average, there was one late-arriving result for almost every patient. And nearly 10 percent of results could have triggered a change in diagnosis or treatment.
Dr. Dalal developed a computer system that keeps track of postdischarge tests, and when a result comes back after a patient has gone home, it is automatically e-mailed to both the doctor who ordered the test and the patient’s primary care physician. The system was piloted at the hospital last year, and Dr. Dalal hopes to enact it throughout the hospital later this year. That will be good for the Brigham hospitals, but it’s just a start.
Until these kinds of practices become universal, patients like the man with disabling stomach pain are at risk of remaining without a diagnosis, even when one is at hand.
Dr. Palmon is all too aware of this possibility. He routinely checks old charts of all new patients. And these days he finds himself sending off urine porphobilinogen tests on a lot of his patients with unexplained belly pain. He hasn’t made any more diagnoses of porphyria, but he’s determined never to miss it if another patient comes under his care.