Differential diagnosis resources

Although I trashed last week’s controversial New York Times article about misdiagnosis the article was not totally devoid of substance. It pointed me to Isabel, a web based differential diagnosis reminder system. It’s named after Isabel Maude, the girl with chicken pox and a delayed diagnosis of necrotizing fasciitis who was profiled in the New York Times story. When Isabel was on the mend at the tertiary care center, staff there began hinting that the case had been mishandled. The parents were angry and friends urged them to sue. Instead, Jason Maude decided to direct his energies more constructively. He founded a software company to develop a program to help physicians improve diagnostic accuracy.

How does it work? Typing in the patient’s presenting signs and symptoms yields an extensive list of possible diagnoses, with the idea that the physician will be reminded of rare diseases or uncommon presentations of more common diseases which might otherwise be overlooked. Isabel started out as a pediatric resource but has since been expanded to include adult medicine.

Other differential diagnosis resources are out there. I’ve had some experience with Dxplain, a program from Mass General. Although Dxplain is primarily licensed to institutions, a free portal is available for individual subscribers to Merck Medicus. I occasionally use Dxplain and have signed up for a free trial of Isabel. I’ll plug a few cases into both programs for comparison and report back soon.

Meanwhile the web version of the New York Times article links to an audio interview of Jason Maude. (Check the left sidebar). He discusses his daughter’s case and the history of development of the Isabel program. It gets a little self promoting at the end. Jason suggests patients ask their doctor “Have you tried Isabel?” There’s talk of developing a consumer version. Now that could get interesting. Imagine your patient with gastroenteritis telling you “I did an Isabel search and it told me vomiting can be due to a cerebellar tumor or hemorrhage. I want an MRI.”