The website that knows what doctors don't

Vital Signs is a monthly program bringing viewers health stories from around the world.

(CNN)How does a doctor diagnose something they've never seen before?

One answer comes in the form of online tool VisualDx, a website and app used by medics to solve clinical conundrums -- in real-time.
Doctors use the site by typing in the symptoms they see on their patients to bring up a list of possible causes and accompanying images. The more clues they type in, the more specific their options become. It's then a case of matching what they see on their screen to what they see on their patient to make an informed diagnosis.
Diseases can also be looked up based on other factors including countries a patient has recently visited or activities they've done, such as camping, to bring up associated risks and diseases.

    Searching for an answer

    With more than 1,300 diseases on file -- and 1,500 more to be added by September 2015 -- it covers a wide range of medical conditions.
    "About 99.9% of all visits to clinicians are for under 500 diseases," says Dr. Art Papier, founder and CEO of VisualDx. "[But] there's a lot of error around common diseases," he says.
    According to the Society to Improve Diagnosis in Medicine, 5-15% of diagnoses are estimated to have errors.
    When a doctor makes a diagnosis, they're against the clock to sift through an array of potential diseases. "[Doctors] have to make fast-paced decisions," says Papier.
    The image-led nature of the app accommodates this pace.
    "You describe what you're seeing and that shows [image-based] diagnoses that include what you're seeing," says Dr. James Willig, an infectious disease specialist at UAB hospital in Alabama -- and VisualDx user.
    The ability to search and sift through a database of images in this way helps doctors like Willig diagnose faster and -- importantly -- more accurately. Having accessible information at their fingertips can also improve trust and rapport with patients.

    Facing the unknown

    The scenario today is more complex than ever before. Increased global travel and exposure to new infections means patients are often arriving at clinics with symptoms unseen by their doctors before.
    A prime example is the mosquito-borne Chikungunya, a debilitating infection originating in Asia which arrived in the Americas at the end of 2013 -- and continues to be transmitted today.
    "My colleague diagnosed the first case of Chikungunya in the state of Alabama," says Willig whose hospital has seen a number of Chikungunya cases. But this exposure to the unknown is nothing new as his hospital is a referral center for Alabama and its surrounding states. "We get just about everything," he says.
    With more than 150,000 images already available, VisualDx is helping clinicians like Willig readily identify what their patients are suffering from and particularly lends itself to skin-based symptoms such as rashes and ulcers, which are more visible.
    In April 2015, the tool helped Willig identify a rare form of vasculitis on a patient who repeatedly came to his hospital with a "bizarre periodic rash." Willig now uses the site several times a week.

    Visual recall

    The software aims to make it easier for frontline health workers -- the general practitioner -- who are expected to know it all.
    "In the past you read books and had to memorize it all," says Papier. "You can't memorize it all."
    The technology was launched in 1999, and more than 100 million images have been viewed to date.
    "Medicine is richly visual, and probably more so than most people appreciate," says Dr. Joshua Landy, creator of medical photo sharing app, Figure-1. "As clinicians, we use our eyes in assessing patients more frequently than we realize. Having clinical decision support in that same visual medium allows one to make a visual comparison side-by-side."

    Patient diversity

    A large challenge facing clinicians is that people suffering from the same disease can manifest the condition differently, meaning their symptoms can look different -- particularly on different skin colors.
    "People present in different ways," says Dr. James Shoemaker, emergency physician at Elkhart General Hospital, Indiana -- who uses the app every day for more rapid diagnoses. "This has pictures of different skin colors," he says.
    When symptoms of a disease are mainly skin-based, the need to understand how they appear on different skin colors is crucial. The image collection and processing for VisualDx encompasses this and enables visual comparison of symptoms for example in Caucasians and Latino people.
    "There's no shift where you don't see something you've never seen before and it's nice to have that reinforcement," says Shoemaker.

    Global spread

    According to VisualDX, more than 1,500 hospitals and clinics in the United States and more than half of the nation's medical schools use its product in their diagnostics, and it's also used in Europe and Asia.
    But Papier wants the program to broaden its horizons -- and diseases.
    "We want to bring this worldwide," he says. "[We want this to be] an ultimate diagnostic tool for any physician around the world."