Editor’s Note: Dr. Julie Evans (she/her) is a resident physician in pediatrics at the University of Virginia. She is interested in general pediatrics and global health. -Rachel Y. Moon, MD, Associate Editor, Digital Media, Pediatrics
Measles is a virus that was once a fixture of childhood. Luckily, most children who get measles improve without serious problems, but complications include pneumonia, encephalitis with lasting neurological problems, and subacute sclerosing panencephalitis (SSPE), which is almost always fatal.
Although we have a vaccine that prevents measles, there has been a measles resurgence due to decreasing vaccination rates. However, many pediatricians have never seen a case of measles, making it hard to diagnose.
To tackle this knowledge gap, Dr. Caitlin Naureckas Li from Lurie Children’s Hospital and colleagues provide experience and insight from clinicians and the literature about measles in their article entitled “What’s Old is New Again: Measles,” being early released in Pediatrics this week (10.1542/peds.2025-071332).
Readers are first taken through the history of the measles vaccine, with the result being today’s current MMR vaccine, which is 97% effective after 2 doses.
Presentation of measles is highly characteristic:
- Cough
- Conjunctivitis (redness of the whites of the eyes)
- Runny nose
- Fever
- Koplik spots (tiny white macules on a red base, which appear early in illness)
- Morbilliform rash (which starts at the hairline, moves down the body)
Measles is one of the most contagious infections that exists; typically one person with measles will infect up to 18 people in an unvaccinated community. People with measles are contagious beginning 4 days before their rash until 4 days after their rash and should be isolated with airborne precautions.
When one is concerned for measles, the CDC recommends polymerase chain reaction (PCR) testing to confirm the diagnosis.
Treatment for measles is supportive. Vitamin A helps reduce mortality in children under 2 years in low- and middle-income countries; however, because both vitamin A deficiency and measles can damage epithelial tissue and affect immune function, and the combination can result in increased risk for secondary infections, the World Health Organization (WHO) and American Academy of Pediatrics (AAP) recommend 2 doses of vitamin A for all children with measles. Vitamin A will not prevent or cure measles nor prevent complications.
Complications of measles are common, and children with immunocompromising conditions are at greatest risk. Over half of children with measles will develop pneumonia. Encephalitis (inflammation of the brain) occurs in 1/1000 people. SSPE is a fatal late complication with slow progressive deterioration and no treatment.
To prevent measles, most importantly, get vaccinated! The MMR vaccine should be given to anyone not immune to measles and those over 6 months of age within 72 hours of exposure to measles. The AAP has resources to help clinicians counsel parents and encourage vaccination.
Read this article so that you are well prepared if you see a patient with measles. Check out table 1 for steps to take to prepare for local measles outbreaks, and continue to advocate for vaccines.
