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Diagnosing Measles in Light of Recent Outbreaks

chest_rash.jpgThe CDC declared it eliminated from the United States 19 years ago, thanks to widespread vaccine use. But now, measles is making a comeback in a time when many practicing primary care physicians and pediatricians have not seen the disease firsthand.

As of February 2019, nine states have reported cases of measles in 2019 (CDC), which includes four current outbreaks. Washington is under a state of emergency for an outbreak with 38 cases, and the number continues to grow. New York has seen 200 cases across a handful of countries.

The concern with measles is that it travels through the air and is highly contagious. The telltale rash usually doesn't develop until 4 days after infection, so people unknowingly spread the infection to others before realizing they have measles. Children in Washington with confirmed measles have visited 56 public places in Washington and Oregon (including 2 daycare centers, 11 healthcare centers, 12 schools, the Portland airport, and a Portland Trailblazers game). Officials believe that because of this mass exposure, the number of measles cases will increase. koplik_spots.jpg

As the numbers grow, more clinicians will encounter a disease they've only seen in textbooks. Christian Hietanan, DO, said on Twitter, "There have been over 100 cases of Measles in the county just south of my medical school. In 15 years of practicing pediatrics, I've never seen a case of it, but I'm always worried that I'm going to miss it."

Measles - What should you look for?

  • Remember the three Cs of measles: cough, coryza (stuffy nose), and conjunctivitis
  • Phases:
  • 1) Starts off with a fever and a hacking cough
  • 2) 3-4 days later, Koplik spots show in the mouth opposite the second molars
  • *Koplik spots are small white papules that may or may not have a blue dot in the middle
  • 3) Rash starts after Koplik spots
  • *Begins on the head and travels down to the trunk and the extremities

Measles can look like infectious mononucleosis, erythema infectiosum, roseola, rubella, an enteroviral infection, Kawasaki disease, Rocky Mountain spotted fever, or an exanthematous drug eruption,

head_rash.jpgMeasles can be prevented with the MMR vaccine, and doctors across the country encourage everyone who can to get the vaccine. The CDC says two doses of the MMR vaccine are about 97% effective at preventing measles; one dose is about 93% effective.

You can learn more from public health resources including CDC, Mayo Clinic, and your state health department.

VisualDx also has plenty of resources to help recognize, understand, and diagnose measles. Watch our Spotting Measles webinar; view 84 medical images across a variety of ages, skin tones and disease stages; and review concise, peer-reviewed disease information. To help your patients understand their diagnosis, you can print out or email a patient handout, written with the patient in mind, in both English and Spanish.

About VisualDx

VisualDx is an award-winning diagnostic clinical decision support system that has become the standard electronic resource at more than half of U.S. medical schools and more than 1,500 hospitals and institutions nationwide.  VisualDx combines clinical search with the world's best medical image library, plus medical knowledge from experts to help with diagnosis, treatment, self-education, and patient communication. Expanding to provide diagnostic decision support across General Medicine, the new VisualDx brings increased speed and accuracy to the art of diagnosis. Learn more at