Understanding Measles: Symptoms and Stages Explained

January 14, 2025

Measles, a disease once declared eradicated in the United States in 2000, is making a troubling comeback. This highly contagious illness, which poses significant risks to children, is on the rise again. Just before we entered the new year, the Centers for Disease Control and Prevention (CDC) reported that there were 284 measles cases reported across several jurisdictions. A bulk of these were found in children under the age of 5. For parents, this rise in cases is an opportunity to understand the stages of measles and how vaccines play an important role in preventing its spread and protecting their families from its potentially serious consequences.

How Serious is Measles?

Very. Measles is a highly contagious viral illness caused by the measles virus, known for its airborne transmission and potential severity. Before the introduction of the measles vaccine, the disease caused significant damage in the U.S., with an estimated 48,000 hospitalizations and 400–500 deaths annually. Although measles is not a seasonal virus, it often spreads during high travel periods, such as spring break, or in close-contact settings like summer camps, particularly among unvaccinated individuals. Recognizing the symptoms and understanding the stages of measles is essential for early detection and proper care.

Stages of Measles

Measles has three main stages, each characterized by distinct symptoms and progression:

Incubation Period (7–14 Days)

This is the period after exposure to the virus and before symptoms appear. During this time, the virus replicates in the respiratory tract and spreads to the lymphatic system. At this stage, there shouldn’t be any noticeable symptoms, and individuals are not yet contagious.

Prodromal (Initial) Stage (2–4 Days)

Symptoms start to appear, often resembling a common cold or flu. Common signs include:
Fever (often high, above 101°F or 38.5°C)
Runny nose
Cough
Red, watery eyes (conjunctivitis)
Sore throat
During this stage, tiny white spots with bluish centers start to develop inside the mouth, typically on the inner cheeks. This is a unique feature of measles and can help with early diagnosis.

Exanthem (Rash) Stage (3–7 Days)

The measles rash is the most recognizable symptom. It starts as flat red spots on the face and hairline and gradually spreads downward to the neck, trunk, arms, legs, and feet. Some of the spots may become slightly raised.
Other symptoms during this stage can include:
Persistent high fever, which may peak above 104°F (40°C)
Intensified cough and runny nose
General discomfort and fatigue
The rash typically lasts about 5–6 days before fading.

Complications of Measles

Once contracted and not properly dealt with, measles can lead to complications, especially in young children, pregnant women, or those with weakened immune systems. Potential complications include:

Ear infections: Measles can lead to otitis media, causing ear pain and potential hearing issues.
Diarrhea: A common complication, especially in children, that can lead to dehydration.
Pneumonia: This serious complication occurs when the virus affects the lungs and is a leading cause of measles-related deaths.
Encephalitis: A rare but severe inflammation of the brain that can cause seizures, permanent brain damage, or, in rare cases, death.
Subacute sclerosing panencephalitis (SSPE): A very rare, progressive, and fatal disease of the central nervous system that can develop years after a measles infection.

When to Seek Medical Attention

If you suspect measles or notice symptoms such as high fever, widespread rash, or white spots inside the mouth, it’s important to get in contact with a healthcare provider. Early diagnosis not only helps in managing symptoms but also prevents the spread of the virus to others.

Seek immediate medical attention if:

The individual experiences difficulty breathing or persistent chest pain.
Symptoms worsen after initial improvement.
There are signs of dehydration, such as reduced urination, dry mouth, or extreme fatigue.
Neurological symptoms like confusion or seizures occur.

The Impact of Declining Vaccination Rates

One major reason for the rise in measles cases in the U.S. is the decline in childhood vaccination rates. According to the CDC, less than 93% of kindergartners were vaccinated against measles during the 2023–2024 school year, a drop from 95% in 2019–2020. Vaccination rates against other diseases, including polio and whooping cough, have also fallen.

The most effective way to prevent measles is through vaccination. The Measles, Mumps, and Rubella (MMR) vaccine has been proven to give protection against the virus and has significantly reduced measles cases worldwide.

Keeping a Calm Perspective

While measles is a serious illness, knowledge is power. By recognizing and understanding the symptoms, stages, and complications, you can take proactive steps to prevent illness. If you or someone you know shows signs of measles, consult a healthcare professional for guidance. Early recognition and supportive care are key to managing the illness effectively.