Measles – Symptoms and Causes

Overview

Measles is a viral infection that mainly affects children. This highly contagious disease can spread easily from person to person. Though once very common, vaccines have greatly reduced measles cases worldwide.

The disease creates a distinct red, blotchy rash. This rash typically starts on the face and behind the ears. It then moves downward, covering the chest and back before reaching the feet.

Despite vaccination efforts, measles remains dangerous. It causes more than 200,000 deaths yearly, with children being the most affected group. The illness can lead to serious complications and can be fatal, especially for young children with weak immune systems.

In the United States, measles cases have become rare over the past twenty years due to high vaccination rates. Most recent cases in the U.S. come from outside the country.

These cases typically affect people who haven’t received vaccines or aren’t sure about their vaccination status.

Signs and Symptoms

Measles is an infection that develops in stages over a 2-3 week period. The virus typically shows its first signs about 10-14 days after a person is exposed.

When Can Someone Spread Measles?

People with measles can pass the virus to others for approximately 8 days total. This contagious period begins 4 days before the rash appears and continues until 4 days after the rash first shows up.

This means someone can spread measles before they even know they’re sick.

The infection follows a predictable pattern:

Stage 1: Incubation Period (10-14 days)

• The virus multiplies in the body
• No visible symptoms appear
• Person is not yet contagious

Stage 2: Early Symptoms (2-3 days)

• Mild to moderate fever
• Persistent cough
• Runny nose
• Red, watery eyes (conjunctivitis)
• Sore throat

Stage 3: Distinctive Signs (1-2 days)

• Tiny white spots with bluish-white centers inside the mouth (Koplik’s spots)
• These spots appear on a red background on the inner cheek lining

Stage 4: Rash and High Fever (about 7 days)

• Small red spots, some slightly raised
• Rash begins on the face
• Spreads downward to arms, chest, back, thighs, and feet
• Fever spikes dramatically (up to 104-105.8°F or 40-41°C)
• Spots cluster together, creating a splotchy red appearance

Stage 5: Recovery Period

• Rash fades gradually, starting with the face
• Finally disappears from thighs and feet
• Cough may persist
• Skin may darken or peel where rash appeared
• Some symptoms can last up to 10 days after the rash begins fading

When to Get Medical Help

Contact your healthcare provider if you suspect you or your child has been exposed to measles, or if a rash resembling measles appears.

It’s important to check your family’s immunization records with your provider, particularly before children begin attending daycare, school, or college. Also, review vaccinations before traveling internationally outside the United States.

Always keep vaccination records up to date to ensure proper protection against preventable diseases.

Causes

Measles is a highly contagious disease caused by a virus that resides in the nose and throat of infected individuals.

The virus spreads primarily through the air when an infected person coughs, sneezes, or talks, releasing infectious droplets that can be breathed in by others.

These airborne droplets can remain active in the air for about an hour. The virus can also land on surfaces where it survives for several hours.

People can become infected by touching these contaminated surfaces and then touching their eyes, nose, or mouth.

The contagious period extends from approximately four days before the rash appears to four days after it develops. Without vaccination or previous infection, about 90% of people exposed to the measles virus will contract the disease.

Transmission methods:

• Airborne respiratory droplets
• Direct contact with infected surfaces
• Person-to-person contact

Important note: Individuals are most contagious during the days before the characteristic rash appears, often before they even know they’re infected.

Risk Factors

People face higher chances of getting measles in certain situations:

• No Vaccination: Those who haven’t received the measles vaccine have a much higher risk of catching the disease.

• International Travel: Visiting countries where measles occurs more frequently increases exposure risk.

• Vitamin A Shortage: People with inadequate vitamin A in their diet may experience more severe symptoms and complications if they catch measles.

These factors significantly affect who gets sick and how badly the illness might affect them.

Complications

Measles can lead to several health issues beyond the typical symptoms. These problems may be mild or severe, depending on the person’s health.

Stomach issues like diarrhea and vomiting are common complications. These can cause dehydration if not managed properly.

Infections often develop during or after measles. Bacterial ear infections are very frequent in measles patients. The respiratory system can also be affected in several ways:

• Inflammation of airways (croup)
• Bronchitis (swelling of lung passageways)
• Laryngitis (voice box inflammation)

Pneumonia is a serious lung infection that commonly occurs with measles. People with weakened immune systems face higher risks from this complication.

Brain inflammation, called encephalitis, affects approximately 1 in 1,000 measles patients. This dangerous condition can cause permanent brain damage. It might develop immediately or appear months after recovery from measles.

Pregnant women must be especially careful to avoid measles exposure. The disease can cause:

• Premature birth
• Low birth weight babies
• Fetal death

People with compromised immune systems face the highest risk for developing severe complications from measles.

Ways to Prevent Measles

Childhood Vaccination

The measles-mumps-rubella (MMR) vaccine is the main way to prevent measles in children. Health experts recommend two doses: the first between 12-15 months old and the second between 4-6 years old, before starting school.

With both doses, the MMR vaccine is 97% effective and provides lifelong protection. The few people who get measles after vaccination usually have mild symptoms.

Important points to remember:

• For international travel with babies 6-11 months old, talk to your doctor about early vaccination
• Children who missed the recommended schedule may need two doses four weeks apart
• Babies born to immune mothers usually have protection for about 6 months
• Early vaccination (before 12 months) still requires regular doses later

The vaccine may be given as MMRV, which includes protection against chickenpox. Side effects are typically mild and may include fever or soreness at the injection site.

Adult Vaccination

Adults may need the measles vaccine if they:

• Have higher exposure risk (college students, healthcare workers, international travelers)
• Were born in 1957 or later without proof of immunity

You have proof of immunity if you have:

• Written documentation of proper measles vaccination
• Lab test results show immunity
• Medical records confirming previous measles infection

Most people born before 1957 in the U.S. are already immune because they had measles as children. If you’re unsure about your status, consult your healthcare provider.

Managing Exposure

When someone in your household has measles, take these steps to protect others:

• Keep them home. Measles is highly contagious from about 4 days before the rash appears until 4 days after. The infected person should avoid contact with others during this time.

• Separate the unvaccinated. People without immunity should avoid the infected person.

• Get emergency vaccination. Anyone at risk who isn’t fully vaccinated should get the measles vaccine as soon as possible, including babies over 6 months.

During community outbreaks, health departments might recommend additional precautions, such as earlier vaccination schedules. However, if you’ve already had two MMR doses, a third isn’t typically recommended.

Stopping Disease Spread

Vaccination is crucial for:

• Building community protection. Since the measles vaccine was introduced, the disease was nearly eliminated in the U.S. This happened because of “herd immunity,” where enough people are vaccinated to stop the disease from spreading.

• Preventing outbreaks. When vaccination rates drop, measles cases increase. For example, in 2008, England and Wales reported nearly 1,400 confirmed measles cases after vaccination rates fell.

Recent years have seen a concerning rise in U.S. measles cases, likely due to declining vaccination rates in some communities.