Editor’s Note: This article was originally published in the June 2014 issue of Vaccine Update. Given recent cases of measles and warnings about the spread of measles from the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO), we thought it was a good time to update and republish it.

Would you recognize a case of measles if an infected patient entered your office or clinical setting? Many younger clinicians today have never had to diagnose a patient with measles — an attestation to the effectiveness of the measles vaccine. Indeed, measles is one of the most contagious infectious diseases. It hangs in the air for a few hours after an infected person leaves the area, meaning that a person can spread the virus to people they never even come into physical contact with.

So, what does this mean for healthcare providers?

Measles can be confused with other illnesses, including Kawasaki disease, dengue and scarlet fever, among others, because of its common presentation as a rash accompanied by fever. When a patient has these symptoms, the following should also be considered to help distinguish measles from other possible illnesses:

  • Recent travel, particularly to measles-endemic regions.
  • Two to four days of cough, coryza, conjunctivitis, and aversion to light prior to onset of fever and rash.
  • Presence of Koplik’s spots on the back of the palate — the spots are irregular in shape and red with blue-white centers.
  • Rash that typically starts at the hairline and progresses from head to trunk to extremities.
  • Resolution of fever shortly after rash develops.

Children presenting with measles typically appear to be miserable.

What if I suspect that a patient has measles?

Patient isolation and measles containment

Measles is one of the most contagious diseases, spreading commonly, but not solely, via large droplets. The virus is so contagious that if a susceptible person occupies an elevator or other enclosed space up to two hours after a person infected with measles, he or she is likely to be infected. The period of highest contagion is four days before to four days after onset of rash. Because of this ease of spread, it is imperative to isolate infected patients from susceptible patients, such as those who are too young to be immunized. Methods for decreasing the chance of transmission in the waiting room include the following:

  • Train front office staff and post signs urging communication and observations related to the presence of respiratory symptoms, rash, or suspected exposure to an infectious disease.
  • Immediately isolate suspected cases in an exam room, or minimally, separate “well visit” and “sick visit” waiting areas.
  • Provide masks for patients — and any symptomatic caregivers — who might be contagious, if possible.
  • Implement special precautions so that immune-compromised patients are aware that they should alert front office staff of their increased susceptibility upon arrival.

Current isolation precautions can be accessed on the CDC’s website.

Laboratory confirmation

Get a serum sample and either a throat or nasopharyngeal swab from the patient. A urine sample may also contain measles virus proteins, but throat or nasopharyngeal swabs are preferred over urine samples. The most common tests are an IgM test and a real-time polymerase chain reaction (RT-PCR) test; either of these can typically be used for laboratory identification of measles. The CDC has a comprehensive section on its website related to measles lab tests.

Health department notification

Suspected cases of measles should be reported to local public health officials as soon as feasible, and health departments are required to report cases to the CDC within 24 hours. Find out more about what information will be needed from the CDC’s surveillance manual.


The MMR vaccine should be given at 12 to 15 months of age with a second dose between 4 and 6 years of age as recommended on the approved immunization schedule. Measles outbreaks provide a compelling argument for choosing not to delay receipt of the MMR vaccine. Three studies provide additional reasons for children to be immunized as soon as they are of age:

  • Delayed immunization (in the second year of life) increases the risk of febrile seizures — A 2014 paper in Pediatrics (PDF) by Simon J Hambidge and colleagues found that when the MMR (or MMRV) vaccine was given between 16 and 23 months of age, the risk of experiencing a fever-associated seizure following the vaccination was significantly greater than when the vaccine was given between 12 and 15 months of age.
  • Risk of suffering the fatal complication of measles known as subacute sclerosing panencephalitis (SSPE) is greater following infection with measles at an earlier age  — This 2013 paper from Germany by Katharina Schönberger and colleagues identified cases of SSPE in Germany and attempted to calculate the risk of developing this complication following an acute measles infection. Although the data set was small, their finding, that the risk of developing SSPE is greater in individuals who are infected with measles in the first few years of life than in those who are infected later, agrees with findings from other studies.

    Because maternal antibodies can interfere with the development of a protective immune response in the first year of life, the authors conclude by pointing out that the findings related to SSPE make the protection afforded by strong herd immunity in the first year of life even more important.
  • A more recent paper (2023) published in The Journal of Pediatric Infectious Diseases by Campbell and colleagues demonstrated SSPE trends based on increased cases of measles in the UK, citing a recurrence of SSPE diagnoses after a 15-year period of no cases. The resurgence followed an increase in cases of measles in the UK between 2006 and 2013.

For more information about measles, check these resources:

  • Doctors Talk: Measles — In this video, Drs. Paul Offit and Katie Lockwood discuss measles, including concerns about spread in waiting rooms and how to diagnose measles.
  • Why are we seeing measles outbreaks? — Video featuring Dr. Paul Offit, VEC Director, discussing recent cases of measles as related to the history of measles vaccine mandates in the U.S.
  • Rash information — Go to “Measles – viral” section of page for info about measles; however, the page also has information about other rash-related illnesses that may be confused with measles.
  • Think Measles — This one-page document from the American Academy of Pediatrics includes key information when it comes to diagnosing measles. Be sure everyone on your team has an opportunity to review it.

Looking for resources to share with families? Check these VEC resources:

Hearing misinformation about measles and the vaccine? SciCheck has addressed recent concerns that are circulating, “Posts Mislead About Measles, MMR Vaccine Amid Recent Outbreaks.”

Materials in this section are updated as new information and vaccines become available. The Vaccine Education Center staff regularly reviews materials for accuracy.

You should not consider the information in this site to be specific, professional medical advice for your personal health or for your family's personal health. You should not use it to replace any relationship with a physician or other qualified healthcare professional. For medical concerns, including decisions about vaccinations, medications and other treatments, you should always consult your physician or, in serious cases, seek immediate assistance from emergency personnel.