IDdx was built for queries. Users can find lists of matching infectious diseases by picking disease search criteria. The user can see all the symptoms associated with a disease or see all the diseases associated with a symptom.

New features added in January 2015 are Ranked Diseases and Weighted Findings. Ranked Diseases means that the user can sort the list of diseases returned from a query by cases/years in either the U.S. or worldwide. Weighted Findings means that color coding indicates how frequently a finding is used to describe the disease in the twelve primary references. The findings of a disease are included only if they are published in the primary references. Weighted Findings enables another new feature: Query Sensitivity. Choose High to get the most diseases that match one or more signs & symptoms. Choose Low to get only those diseases in which the finding was cited in three or more of the 12 references. Background updating gives users the latest information on a daily basis--no manual updating of the app required.

"A remarkable infectious disease tool that combines ease of use with up to date epidemiological data that could truly help providers make the correct diagnosis at the point of care."
- []

IDdx was picked as one of the 25 best nursing apps!

- Explore the database of 250 diseases in 15 categories.
- Search by disease Name or Criteria.
- Disease criteria include 104 signs & symptoms, 39 epidemiological factors, and 16 regions of the world.
- Search by Occupation. Results are sorted by high-risk job tasks.
- Search by one or more incubation periods.
- Examples of epidemiological factors are ingest (entry), soil (source), ticks (vector), and cats (reservoir).
- Access diseases worldwide or limit the search to those endemic to the United States.

WHAT IS THE CONTENT? - Similar to the Control of Communicable Diseases Manual, the content includes coverage of 250 important infectious diseases organized into the following categories: Arthropod-Borne, Cestodes, Childhood, Foodborne, Gastroenteritis, Immune-Related, Intestinal Nematodes, Localized Infections, Person-To-Person, Sapronoses, Sexually-Transmitted, Tissue Nematodes, Trematodes, and Zoonoses.

WHAT ARE THE SOURCES OF THE INFORMATION? - See this page for the primary and secondary references:

Privacy Policy -

Terms of Service -

What’s New


June 22, 2015
IDdx is now updated with content from Control of Communicable Diseases Manual, 20th edition, published earlier this year. Last year the content of IDdx was updated with the latest edition of Principles and Practice of Infectious Diseases, Wallach's Interpretation of Diagnostic Tests, CDC Health Information for International Travel, and ABX Guide.

Ratings and Reviews

4.8 out of 5
17 Ratings

17 Ratings

New2techno ,

Very impressed !!

Very well organized, complete and easy to use. What other apps have you guys developed?

JAB (author) ,


My goal is to make IDdx as accurate as possible. Signs & symptoms for each disease are the most challenging. I have searched three online textbooks for each sign or symptom. The three online books are Control of Communicable Diseases Manual (CCDM), Principles and Practice of Infectious Diseases (PPID), and Infectious Diseases (Cohen). Use IDdx to help you build a differential diagnosis list. Try to think of two or three criteria that are most important in the case. Try different criteria as you switch back and forth between the results and search screens.

Michael Light ,

Needs improvement

While this app contains very good information, it is not as useful as it could be due to the limitations of the search functionality. Search results are put in alphabetical order. While this may not sound like a problem, there are usually quite a few search results. Since there is no ranking, extremely uncommon diseases whose symptoms only vaguely match the search criteria may be put at the top of the list, burying the useful information. That makes it very difficult to form a differential diagnosis based on the search results. The creators of this software list on their site that their competitor (which is prohibitively costly) has a Bayesian algorithm to rank search results based on prevalence of the disease and how frequently the symptoms searched for appear in that particular disease. Such a function would make the software incredibly useful for forming a differential diagnosis. Even ranking solely on prevalence of the disease would improve the functionality greatly. A good app, but I hope to see great improvement in the future.


Atmosphere Apps, Inc.
22.9 MB

Requires iOS 7.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Infrequent/Mild Medical/Treatment Information
In-App Purchases
  1. Annual Subscription to Premium Version $19.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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