Would You Be Able to Identify Measles in a Patient?

That patient’s cough or runny nose might just be a cold — but what if it’s measles? A growing number of Americans and their doctors may find themselves asking this question. Understanding the signs and what to do if you see them in a patient may be a key in limiting spread.

Twelve US states have had measles outbreaks this year, including Texas, where a child died from measles last month. (A second death in New Mexico may be from measles but is still under investigation.) The Centers for Disease Control and Prevention (CDC) reported 222 measles infections so far in 2025, approaching the total number of cases in all of 2024 (N = 285).

Measles spreads easily among people without immunity, those not protected by a past measles infection, or by the MMR vaccine (for measles, mumps, and rubella). Two doses of that are 97% effective at preventing measles.

Measles is extremely contagious.

“Most viruses don’t linger in the air for hours after somebody has coughed or sneezed,” said James Conway, MD, a professor of pediatrics at the University of Wisconsin-Madison School of Medicine and Public Health in the Divisions of Infectious Diseases and Global Pediatrics.

“Measles does,” he said.

If your patients are not vaccinated, measles is easy to catch, and it can be difficult to spot in its early stages. The first symptoms don’t appear until 11-12 days after exposure and can be easy to dismiss. Patients may think they just have a regular cold or flu.

In a recent case in Kentucky, a person infected with measles unknowingly exercised at a gym while contagious. “This is somebody who got home from travel, was infected by measles, and was capable of working out for three hours at a Planet Fitness on President’s Day,” said Conway. Health officials issued an alert to anyone who had been at the gym.

Measles sometimes takes a deadly turn. Doctors and researchers share how to tell if you or your patient has measles and what to do next.

Are the Symptoms of Measles Obvious?

Eventually, measles causes telltale symptoms, like a blotchy red rash that starts on the face before traveling down the body. Tiny white or gray spots can also appear inside the mouth. Unfortunately, these visible symptoms aren’t early warning signs — they don’t show up until 2-4 days into the illness.

The first symptoms of measles, like a fever, cough, pinkeye, and runny nose, can feel like a run-of-the-mill respiratory virus. Measles might not cross your patient’s or your mind initially.

“Measles can be a very difficult diagnosis, given the timing and nature of symptoms,” said Erik Blutinger, MD, MSc, an assistant professor of emergency medicine at the Icahn School of Medicine, New York. People with early measles symptoms might undergo multiple tests to rule out other causes, he said. It might take more than one visit before a doctor orders a measles test.

But it’s this early symptom period, known as the prodrome, when patient sick with measles can put others at risk. “Measles is most contagious in the prodromal illness,” said Walter A. Orenstein, a professor emeritus in the Emory School of Medicine, Atlanta.

How Do Measles Symptoms Progress?

By the time the itchy, painful measles rash appears, other symptoms might be escalating. “For most people who get measles, it’s a fairly significant illness,” Orenstein said. “It’s not trivial.”

Measles can cause a fever of 104 or 105 °F, intense cough, ear infections, diarrhea, and pneumonia that requires hospitalization. “As the virus spreads throughout the whole body, it certainly has a predilection that it likes to cause inflammation throughout the lining of the lungs,” said Conway.

The virus can also infect the central nervous system. About 1 in 1000 children with measles develop encephalitis, or swelling in the brain. “They have a rip-roaring headache — it’s almost like having meningitis,” said Conway. “Some will even get neurologically impacted to the point where they’re confused or almost nonresponsive.” Severe cases can cause permanent hearing loss or intellectual disability.

Then, there’s the worst-case scenario: 1 to 3 of every 1000 infections causes death.

There’s no antiviral medication for measles. Healthcare providers can only provide supportive care, like intravenous fluids for dehydration or vitamin A to support depleted immune function.

Even people who fully recover can struggle for a long time, said Conway, who has treated children with measles in the United States and abroad.

“These little kids just cry for days,” said Conway. “Every kid I’ve ever seen, they’re just miserable. They gradually recover, but they take a pretty big hit, and then their nutrition is down for a while because they don’t eat and drink very well. The GI [gastrointestinal] tract is a mess. Their lungs are a mess. And so the recovery is, for many of these kids, a couple of months.”

Adults can be affected too. “Measles can easily become a severe illness to anybody, especially those who are considered high risk of contracting the illness, like healthcare workers, pregnant individuals, and those with immunocompromised systems,” said Blutinger.

Measles kills immune cells and causes lasting damage. “Another risk is what’s called post-measles immune amnesia,” said James D. Cherry, MD, MSc, a distinguished professor of pediatrics at the David Geffen School of Medicine at University of California, Los Angeles. “When you have measles, you’re more susceptible to other infectious diseases for a period of up to 5 years.”

What Should I Do if I Think My Patient Might Have Measles?

If your patient is sick and they live where measles is spreading — more information is available on the CDC website or through your local public health department — then contact your healthcare provider for advice.

In some patients, a watch-and-wait approach may be most appropriate. One in five people who have gotten sick in this year’s outbreaks have gone to the hospital, the CDC reports. When measles leads to hospitalization, it’s for treatment, not quarantine. “We generally try to do everything we can to avoid admitting these kinds of patients to the hospital, unless we absolutely have to, because measles is by far the most contagious thing on the face of the Earth that we know of at this point,” said Conway.

Depending on immune status and underlying conditions, physicians may recommend an MMR vaccination within 3 days of the exposure or measles immunoglobulin, which contains antibodies to boost your immunity, within 6 days of the exposure.

“For persons who are not immune, have an unknown immune status, or are immunocompromised, it is especially important to react quickly so that you don’t miss that window of opportunity where you might be able to prevent the infection, or at least make it less severe,” said Margaret Doll, PhD, MPH, associate professor of epidemiology at the Albany College of Pharmacy and Health Sciences, Albany, New York.

How Can Patients Avoid Measles?

“The first thing every family should do is make sure everybody in the family is up to date with their vaccines,” said Conway.

Measles vaccination protects patients and those who can’t get the vaccine, like infants or people with compromised immune systems, plus the 3% of people who don’t mount a sufficient immune response after vaccination.

“How are they protected? They’re protected if they’re not exposed,” said Orenstein. “So, community immunity or community protection is important because if a transmitting case only comes in contact with an immune population, the chain of transmission is broken.” (Learn more about how to protect yourself from measles.)

After the COVID pandemic, pediatric vaccinations have declined in the United States. “Given these trends, it’s not surprising that we’re having measles outbreaks,” said Doll. “Measles is a highly infectious disease, and it requires a high percentage of our population to be vaccinated to maintain that herd immunity threshold that stops the transmission of measles.”

This article was originally published on WebMD.