How to Diagnose Measles

Two Parts:Recognizing Measles SymptomsTaking Adequate Precautions

Measles is a highly contagious viral infection caused by exposure to a Morbillivirus. Though this disease was once considered a fact of life for school-age children, thanks to strong vaccination programs, it has now been nearly eradicated.[1] However, since reaching a record low of 37 cases in the U.S. in 2004, case numbers for measles have climbed to a recent high of over 600 in 2014.[2] With this small resurgence, it's all the more important to know the signs of the disease so that treatment can begin as quickly as possible.

Part 1
Recognizing Measles Symptoms

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    Look for cold-like symptoms early on. One of the most frustrating aspects of the measles virus for parents and caretakers is that, at first, it often appears to be nothing serious. For about one to five days before the telltale rash appears, measles usually causes symptoms like those of a cold or flu. These early symptoms usually arise anywhere from 7–21 days after exposure to an infected person:[3]
    • Sore throat
    • Hacking cough
    • Sneezing
    • Runny nose
    • Swollen lymph nodes
    • More rarely, diarrhea
    • General malaise
    • Note: A person with measles can still spread the disease during this early stage.
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    Check for a fever. Measles usually causes a fairly high fever that can peak around 104°F (40°C).[4] This fever can appear before or during the full-body rash that measles is most famous for. Usually, the fever goes away at about the same time the rash does — however, this may not be the case for all measles patients.
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    Look for Koplik's spots inside the mouth. A few days after the initial cold-like symptoms begin, small red spots called Koplik's spots will usually develop on the insides of the cheeks. These spots will have a small white or bluish-white center, making them look like grains of sand, and will often be closely clustered around the areas where the molars touch the cheeks.[5]
    • These spots will persist on their own for a few days before the full-body rash develops. If you notice these spots on yourself or someone else, it is important to take action fast, since these spots indicate that the disease is, in fact, measles, but that it has not yet reached its most contagious stage. See Part 2 below for more information.
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    Watch for a rash that spreads from the head downwards. Within about five days of the initial symptoms, the well-known measles rash appears. This rash usually begins on the forehead, spreads to the rest of the face, and then progresses rapidly down the chest and back, eventually covering the whole body. The rash takes the form of raised, flat red bumps or blotches. Within a few days, the rash should begin to slough off, starting with where it first appeared.
    • At this point, the measles patient is at his or her most infectious. Quarantine at this stage is crucial, as the infectiousness will usually last for about four days after the rash begins.[6]
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    Check for inflamed eyes. The measles rash can sometimes be accompanied by conjunctivitis, a condition of the eyes.[7] Often, conjunctivitis arises when the facial rash is especially bad. This uncomfortable condition can cause symptoms similar to pink eye, including:
    • Inflammation
    • Pink/red appearance
    • Watering
    • Discharge
    • Eyes sealing shut during sleep

Part 2
Taking Adequate Precautions

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    Contact a doctor immediately if you or someone you know has measles. Because measles is highly contagious, it is important to notify your doctor as soon as you suspect you (or someone you know) has it. Although measles is not responsive to antibiotics, your doctor still needs to diagnose your disease, monitor your symptoms, and may even need to treat secondary infections caused by the virus. Most treatment for measles itself is supportive — that is, it's designed to keep your symptoms manageable so that you can get better naturally
    • Don't show up unannounced at your doctor's office with a case of the measles. Always phone ahead. Because measles is so contagious, your doctor may not want measles patients to be near the other patients, especially if they are very young or their immune systems are weakened. Your doctor may, for instance, advise you to use a separate entrance or to wear a mask into the office.
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    Avoid direct contact with others if you have measles. Measles is very, very contagious. About 90% of un-vaccinated people who are around someone with measles will get the disease.[8] While it's not typically a life-threatening disease for healthy people, it can pose serious problems for people in at-risk groups, like the very young, pregnant women, and people with weakened immune systems. Thus, to protect these people, it is very important to do everything you can to prevent others from getting the disease.
    • Staying at home except for medical visits is a must — be sure to contact your work or school to notify them of the situation. Remember that the disease usually stops being contagious about four days after the rash appears. You may want to give yourself an extra day or two of "safety time" on top of this.
    • If you are forced to interact with others, you may want to put on a surgical mask: measles is spread when tiny droplets of moisture expelled from sneezes or coughs are inhaled by another person.
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    Get measles vaccinations for anyone in your family that has not had one. If you or someone in your family has measles or has recently been around someone who has had measles, you may be safe if you have been vaccinated or you can get vaccinated quickly. The measles, mumps, and rubella (MMR) vaccine is very effective at preventing new cases of measles — in fact, after two doses of the vaccine, 95% of people will have immunity to the virus.[9] In some rare cases, it is still possible to get the virus after being vaccinated, but in these cases, the virus tends to be less severe and less contagious.
    • Immunity against measles is usually for life — that is, once you have either received the vaccine or had the illness, you won't be able to get it again.
    • Note: People who were vaccinated before 1968 may still be vulnerable to measles, as early vaccines were not as long-lasting as they are today.[10]
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    Don't believe harmful myths about measles vaccines. Measles vaccines have unfortunately become the source of controversy, leading some parents to keep their children from receiving them. While this may be well-intentioned, neglecting to vaccinate a child against measles can have serious consequences. See below for a few misconceptions about the measles vaccine:
    • The measles vaccine has been linked to autism: False — a single scientific study in the 80s which suggested this possibility has since been discredited.[11] The measles virus itself, however, can very rarely leave children brain-damaged.[12]
    • The measles vaccine is dangerous for healthy people: False — the measles vaccine has the same mild side effects as any other vaccine. In very rare cases, more serious symptoms may occur, but these are less dangerous than the virus itself.
    • The effects of the measles vaccine are not well-understood: False — the measles vaccine has been rigorously studied and tested.
    • The best way for a child to get a measles immunity is to recover from the disease naturally: False — measles can rarely have serious complications, including death, while the vaccine has none. In addition, this "natural" approach puts the lives of immune-compromised individuals in the community at risk.
    • To be clear: The best way to protect a healthy person (and the rest of the community) from measles is with the MMR vaccine.


  • See your doctor if you were vaccinated for measles before 1968 or if you never received a booster vaccination. If you have not contracted measles yet, you may not be immune to it.
  • Nearly all children should receive the measles vaccine at around 15 months.


  • Note that some people, like very young children and those with weakened immune systems, should not receive the MMR vaccine.
  • Although not common, complications from measles include ear infections, croup, pneumonia and inflammation on the brain. These rare but serious complications make the measles vaccine a necessity for anyone who can safely receive it (which is the vast majority of people.)

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Categories: Infectious Diseases