Clinical information

1. How contagious is measles?

Measles is a highly contagious virus, much more contagious than the common cold and even more contagious than other outbreaks like smallpox or Ebola.¹ Measles is potentially transmissible even after brief exposures and at distances up to 30 meters.²

Herd immunity occurs when enough people in a group are immune to a virus or infection that it is hard for the virus to spread. This is also known as community or population immunity.³

The CDC standard of a 95% vaccination rate would result in less than one person being at risk of a measles infection. Below a vaccination rate of 95%, one person with measles can infect up to 18 people (if the vaccination rate is 0%).¹

In some Texas counties, the MMR vaccination rate has reached a nadir of 67%. At this low vaccination rate, one person with measles can spread the virus to five people.¹

2. What are the risks and complications if someone develops measles?

Based on historical data, the CDC has estimated that approximately 1 in 4 cases of measles in the U.S. result in hospitalization, and 1 in 1,000 cases results in death.⁴ Additionally, with increased age, there was a higher risk of complications such as encephalitis, pneumonia, and keratoconjunctivitis.⁴ Other complications include blindness, severe diarrhea and related dehydration, ear infections, and severe breathing problems.⁵

3. What are complications associated with pregnancy?

Measles can cause premature birth and low birth weight if a woman contracts measles while pregnant.⁵ Complications are most common in children under 5, adults over the age of 30, and children who are malnourished or have a compromised immune system.⁵ Most measles deaths occur from disease-related complications.

4. How do dermatologists and other clinicians recognize measles?

The measles virus is usually transmitted from a respiratory illness usually resulting in at least one of the three “Cs” (cough, conjunctivitis and coryzal symptoms) and followed by a characteristic maculopapular rash.

Early symptoms, 4-7 days:

• Runny nose and/or sore throat (coryza)

• Cough

• Red and watery eyes (conjunctivitis)

• Small white spots inside the cheeks (Koplik spots)^5,6

Later symptoms, 7-18 days after exposure:

• Rash

  • The rash usually begins as flat red spots that appear on the face and upper neck, before spreading across the trunk, arms, legs and feet over about 3 days.⁶ The rash usually resolves after 5-6 days.^5,7 Notably, the measles rash typically spares the palms and the soles.

  • Flat red macules may coalesce as the rash spreads across the body.

• High fevers (above 104 Fahrenheit / 40 Celsius) may be associated with the onset of rash.

Examples of Koplik spots

Figure 1. White-blue papules on the buccal mucosa (Koplik spots) of a patient during the prodromal phase of measles. Source: CDC.

Figure 2. White papules on an erythematous base on the buccal mucosa (Koplik spots) of a patient during the prodromal phase (3 days after exposure). Source: CDC.

Figure 3. Erythematous papules on the palate (Koplik spots) of a patient during the prodromal phase (3 days after exposure). Source: CDC.

Examples of measles rash during the eruptive phase

Figure 4. Numerous fine papules on the forehead of a child with measles. Source: CDC.

Figure 5. Scattered dusky macules and papules on the forehead and cheeks of a child with measles. Source: CDC.

Figure 6. Close-up of the characteristic maculopapular rash associated with measles on the cheek of a child. Source: CDC.

Figure 7. Erythematous macules and papules on the forehead of a child with measles. Source: CDC.

Figure 8. Faint exanthem comprising of erythematous macules and papules on the forehead of a child with measles. Source: WHO.

Figure 9. Confluent erythematous macules and patches on the face, neck, trunk, and extremities of a child with measles. Source: CDC.

Examples of measles rash during the convalescence phase

Figure 10. Desquamation on the face, chest, and arms of a child during the third convalescence phase of measles. Source: CDC.

Figure 11. Desquamation on the back of a child during the third convalescence phase of measles. Source: CDC.