If you're working as a medical provider in the clinic, ER and inpatient ward, you'll see patients with fever and rash almost every day, because both symptoms are among common complaints seen in both adults and children patients. Both symptoms can occur in range of diseases, from mild to life-threatening.
The same could apply to other symptoms as well. For example, you've just admitted a patient with a cough. Does he/she have an upper respiratory infection caused by common cold, or is it pneumonia, or something even worse like multi-drug resistant TB?
That's why keeping a broad differential diagnosis is important with just about any complaint, especially if you deal with infectious diseases.
Fortunately, there's IDdx: Infectious Diseases app to help with these difficult decisions, by allowing users to find lists of matching infectious diseases by picking disease search criteria.
Basically, it is a query app that works as a useful decision support tool, which purpose is to build and limit the differential diagnosis based on key symptoms and epidemiological data that users enter into the app. In the query results, users can see all the symptoms associated with a disease or see all the diseases associated with a symptom.
The IDdx app was created by Dr Jay Brown, MD, a family and occupational medicine physician with an MPH from the University of Washington, and a consultant for the US National Library of Medicine, which may explain why the app works so well and provides impressive results.
This app allows you to explore the database of 249 diseases in 15 categories or to search by disease name or criteria. These criteria include 104 signs and symptoms, 39 epidemiological factors, and 16 regions of the world. You can also search by one or more incubation periods, or by occupation, which gives you results sorted by high-risk job tasks. What impresses us is also an ability to access diseases worldwide or limit the search just to diseases endemic to the United States.
As of January 2015, the app added two interesting and useful features called Ranked Diseases and Weighted Findings. Ranked Diseases allow users to sort the list of diseases returned from a query by cases/years in either the U.S. or worldwide. Weighted Findings use color-coding, which indicates how frequently a finding is used to describe the disease in the twelve primary references. In this case, the findings of certain disease are included only if they are published in the primary references.
Weighted Findings also enables another new feature called Query sensitivity. This feature gives you an option to choose from 'High' to get the most diseases that match one or more signs and symptoms, 'Mild', to 'Low' sensitivity, to get only those diseases in which the finding was cited in three or more of the 12 references.
Once you start the app, you'll see Query sensitivity at the top of the screen. We suggest using this feature based on the nature of the query, i.e. the symptoms or disease you're looking for. Sometimes you'll get the better results with High sensitivity, but some queries will require using Low or Mild sensitivity.
Below Query sensitivity, you'll see a list of search criteria from Category, Signs & Symptoms, Epidemiological factors, Endemic to Incubation period, Occupation and Acuity. Tapping on one of the options, expands the search criteria, allowing you to check one or more criteria from initial category.
For example, you can choose Childhood infections from Category, exanthem rash from Signs & Symptoms and incubation period of 2-14 days with Low query sensitivity. You'll get 10 results based on these criteria listed alphabetically or using Ranked diseases feature and sort diseases globally or US based. Since we're based in US, the first result was a strep infection, which confirmed our initial diagnosis. Pages with the results contain links to links to reference websites or apps such as Centers for Disease Control (CDC), Sanford and Hopkins Abx Guide. The IDdx app also links to drug treatment to either CDC or Merck Manual, but is not intended to be a real drug-dosing guide. Users also have an option to bookmark the diagnosis using a little ribbon icon at the top.
The app has a simple, slick and elegant design, with frequent updates based on actual epidemiological data from respected sources. However, navigation is a bit clumsy not allowing jumps within different sections of a particular topic.
Overall, IDdx incorporates the latest edition of Control of Communicable Diseases Manual (CCDM), Principles and Practice of Infectious Diseases (PPID), Infectious Diseases (Cohen), Tropical Infectious Diseases (Guerrant), and numerous other sources from CDC to Hopkins Abx Guide, which makes it true evidence based medicine app, useful to any medical worker dealing with patients with infectious diseases.
Benefit: Any medical provider seeing patients with various infectious diseases would benefit from this app, including primary care, emergency medicine, infectious disease, mid-levels, residents and students.