Infectious Diseases Update: Measles, Not “Just a Rash”

Measles, Not “Just a Rash”

Measles is a highly contagious viral illness that occurs worldwide. Measles has been rare in the United States for several decades. Measles has occurred in brief limited outbreaks over the years, however in 2025 we have already experienced more cases than we have for the last 4 years combined.

Tragically we have witnessed the  first deaths attributed to measles in a decade. An adult, a 6 year old and an 8 year have already died this year of measles. The only known risk factor for severe disease in the children is that they were not vaccinated against measles.

Outbreaks of measles have sporadically occurred in the past, for example in 1990-1991 approximately 1400 people (primarily unvaccinated children) in Philadelphia were infected resulting in many hospitalizations and the deaths of  9 children within a few months time. Paul Offit who was a pediatric infectious disease specialist in Philadelphia states that all 9 of the kids that died of measles were previously healthy and well nourished (but not vaccinated).

The majority of people who get measles will have only mild to moderate symptoms and will recover fully. However, one or more complications occur in approximately 30 percent of measles cases . Diarrhea is the most common complication and can lead to dehydration. Most deaths are due to respiratory tract complications or encephalitis. Pneumonia can occur due to the virus itself, or from a secondary bacterial infection. In the 1940’s (twenty years before widespread measles vaccination) the development and use of effective antibiotics for the treatment of secondary bacterial infections reduced the rate of deaths from measles – although hundreds of people a year continued to die from measles and tens of thousands were hospitalized annually before widespread measles vaccination started in the 1960’s.

A small but significant percentage of people who get sick from measles will have very serious illness and many of those have long term consequences from the infection. The viral infection can damage the brain, gut, lungs and immune system.

Neurologic complications associated with measles include encephalitis, acute disseminated encephalomyelitis and subacute sclerosing panencephalitis.

Encephalitis (brain inflammation) can be caused directly by viral infection or from our immune system. Encephalitis occurs in up to 1 per 1000 measles cases. Signs and symptoms may include headache, vomiting, stiff neck, drowsiness, convulsions, and coma. Approximately 25 percent of children who survive have long term neurodevelopmental problems. Measles encephalitis can be  rapidly progressive and fatal disease occurs in about 15 percent of cases.

Approximately 1/1,000 patients with measles develop acute disseminated encephalomyelitis (*). The condition is treatable but can necessitate medical interventions in an intensive care unit. Subacute sclerosing panencephalitis appears to be more rare but is fatal. Subacute sclerosing panencephalitis (SSPE) is a progressive, disabling, and deadly brain disorder related to measles infection. SSPE is a fatal, progressive degenerative disease of the central nervous system that usually occurs 7 to 10 years after natural measles infection. Why it happens is not well understood but research suggests it may involve persistent infection of the measles virus within the central nervous system. (not all viruses just go away – see my upcoming article on chicken pox and shingles).

Measles virus infection can lead to immune suppression and secondary infections. Secondary and coinfections may include bacteremia, pneumonia, gastroenteritis and otitis media. Measles associated immune defects (“immune amnesia”) may account for increased deaths for up to three years following infection. Several immune system alterations have been associated with measles virus infection making the person susceptible to other infections.

While death, hospitalization and long term health problems can result from being infected with the measles virus most people will only suffer from milder personal consequences of not being vaccinated. Many of the symptoms of measles are common to other respiratory viral infections such as runny nose, cough, fatigue and fever. These symptoms often last for days before the more characteristic signs and symptoms of measles occur. 

Many people with measles will develop small spots inside of the mouth called Koplik spots. These are 1 to 3 mm whitish, grayish, or bluish elevations on a red base. They have been described as “grains of salt on a red background”. Koplik spots often begin to slough when the exanthem appears. People with measles will also often have a sore throat and conjunctivitis (red eyes).

Kopliks spots and the other above symptoms usually are present days before the appearance of the rash that is characteristic of measles. The rash typically starts on the face or neck as red flat or slightly raised spots less than about 1 cm in diameter. The rash then tends to spread to the trunk and then to the arms and legs. The spots may coalesce (run together) to form larger red areas and sometimes can bleed. The rash usually lasts about a week then fades in the order it appeared.

Measles is one of the most contagious viruses known. The period of contagiousness is estimated to be from five days before the appearance of the rash to four days afterward. The illness may be transmitted in public spaces, even in the absence of person-to-person contact. 

According to the National Foundation for Infectious Diseases; “measles is so contagious that if one person has it, up to 90% of non-immune people close to the infected person will be infected”.

The measles vaccine (MMR) is very effective. A small percentage of people who have been vaccinated may develop symptoms if exposed to the virus. However the symptoms are mild and the person is  not highly contagious.

See “Protecting Against Measles” for more information on measles vaccination. 

In my new series “The Art and Science of Medicine” I discuss vitamin A as a treatment for measles. 

As part of the “Health Matters in 2025” series I introduce some points for conversation about the societal issues complicating measles. See Measles Outbreak and Religion for the first in this series.

Please note I am not an infectious disease or public health expert. I am a PA in a rural family practice clinic where I also provide hospital and emergency medicine services. This article is intended for general information and not as personal medical advice. Please see my full listing of  Disclosures, Disclaimers and Context.

The primary source used for this article was the UpToDate article  “Measles: Clinical manifestations, diagnosis, treatment, and prevention”. This article is on the professional medical resource website; UptoDate. This is a well respected subscription based resource that is used by  countless clinicians, hospitals and almost 90% of academic medical centers in the US. The public can access the patient information section at uptodate.com at no charge and I routinely refer patients to this excellent source of information.

For more information specific to infectious diseases please see Health and Medical Resources: Infectious Diseases and Public Health . I have been building this page with a list of resources and will continue to add more information in the future.

Thank you for listening, please share this information with others and let me know what topics you want me to address in the future. I will be continuing my series of articles on fitness and nutrition soon as well as starting a new series on autism. For a full listing of Health Matters Articles click here.

Russ