Porphyria

A 1 November 2009 New York Times Magazine Diagnosis column "Perplexing Pain" by Lisa Sanders MD describes a 46 year old woman with a 23 year history of "attacks of abdominal pain and fever that lasted sometimes for weeks". "None of her doctors had been able to figure out what was causing the strange episodes of devastating illness" that led to a variety of exploratory surgeries and resections of her appendix, both ovaries and much of her colon.  She also reported neurological symptoms:

She’d been losing feeling in her hands and feet for the past couple of years. It started off as a tingling sensation that came and went. Now her hands and feet were always numb. She could barely hold a pen, and she often stumbled because she couldn’t really feel the ground under her feet.

She went to see a neurologist who elicited further history such as very high blood pressure and vomiting during the episodes of abdominal pain, chronic constipation and episodes of bone and joint pain.  The neurologist did an EMG test, but even before the neurological consult, additional history and EMG, the generalist physician had enough information to suggest strongly that the diagnosis was porphyria: click here to see the differential diagnoses using the initial findings in SimulConsult Diagnostic Decision Support.

Her internist was a kind man, she told [her neurologist Dr.] Chelimsky, but it just seemed as if every time he’d come up with some theory about what was going on and treat that, another symptom would pop up. It was like the arcade game her children played, whack-a-mole — you get rid of one problem, but then it would pop back up, along with another and another.

One of the problems with many diagnostic workups is that clinicians use decision trees or narrative material to look for diseases to explain one finding at a time.  A key advantage of diagnostic software is the ability to help evaluate a combination of many different pertinent positive and pertinent negatives occurring at different time periods. 

In this case:

It took more than three months for the patient to get a definitive diagnosis. If figuring out this disease was difficult, testing for it was equally so. But eventually, porphyria was confirmed.

Another advantage of diagnostic software is getting guidance on what findings, including lab tests, are most useful in distinguishing among diseases in the differential diagnosis.  (In the software, click the "Add findings" tab in the software to see such advice, and select or de-select the "Include labs" checkbox as desired.)

Registration is required to click into the software because access to the software is restricted for legal reasons to medical professionals and students.

If you know of interesting cases in the news, in journals or on open Web sites of hospitals or foundations, please contact us and include enough information for us to find the material. The differential diagnosis will change over time as people mull over the case and submit new information to the database about findings in the relevant diseases.