Measles is caused by a virus.
Symptoms include fever, runny nose, hacking cough, red eyes, and a red itchy rash.
The diagnosis is based on typical symptoms and the characteristic rash.
Although the majority of children recover, occasionally measles can be fatal or lead to brain damage.
Routine vaccination can prevent the infection.
Treatment is aimed at relieving symptoms.
Before measles vaccination became widely available, measles epidemics occurred every 2 or 3 years, particularly in preschool-aged and school-aged children. Small, localized outbreaks occurred during the other years. Measles is still common in other countries. Worldwide, each year, measles infects about 20 million people and causes about 110,000 deaths, primarily in children. In the United States, measles is uncommon because of routine childhood vaccination. From 2000 to 2007, an average of only 63 cases per year were reported to the Centers for Disease Control and Prevention (CDC). Now, however, measles cases are increasing in the United States. In the first 6 months of 2019, over 1,000 cases of measles were reported to the CDC. This increase is the result of fewer children receiving the measles vaccine and the result of infection that is spread by travelers or immigrants from areas where measles is more common. Infection that is spread by travelers or immigrants especially occurs in places where many people group together (such as college campuses) or communities that limit contact with outsiders (such as traditional-observant Jewish communities, Amish, and Mennonites).
A woman who has had measles or has been vaccinated passes immunity (in the form of antibodies) to her child. This immunity lasts for most of the first year of life. Thereafter, however, susceptibility to measles is high unless vaccination is given. A person who has had measles develops immunity and typically cannot contract it again.
Children become infected with measles by breathing in small airborne droplets of moisture coughed out by an infected person. About 90% of people who are not immune to measles develop the disease after they are exposed to a person with measles. Measles is contagious from several days before until several days after the rash appears.
Measles symptoms begin about 7 to 14 days after infection. The infected child first develops a fever, runny nose, hacking cough, and red eyes. Sometimes the eyes are sensitive to bright light. Before the rash begins, tiny, bright red spots with white or bluish white centers (Koplik spots) may appear inside the mouth. These spots may resemble grains of sand. Then the child develops a sore throat.
A mildly itchy rash appears 3 to 5 days after the start of symptoms. The rash begins in front of and below the ears and on the side of the neck as irregular, flat, red areas that soon become raised. The rash spreads within 1 to 2 days to the trunk, arms, palms, legs, and soles and then begins to fade on the face.
At the peak of the illness, the child feels very sick and develops eye inflammation (conjunctivitis), the rash is extensive, and the temperature may exceed 104° F (40° C). In 3 to 5 days, the temperature falls, the child begins to feel better, and any remaining rash quickly fades.
Brain infection (see encephalitis) occurs in about 1 out of 1,000 to 2,000 children with measles. If encephalitis occurs, it often starts with a high fever, headache, seizures, and coma, usually 2 days to 2 weeks after the rash appears. The illness may be brief, with recovery in about 1 week, or it may be prolonged, resulting in brain damage or death.
Pneumonia caused by measles infection of the lungs occurs in about 5% of people. In infants, it is a common cause of death. Sometimes, the pneumonia is caused by bacteria rather than the measles virus.
Excessive bleeding may occur after the measles infection resolves because the person's blood platelet levels become low (thrombocytopenia). People usually have bruising of the skin and mild bleeding, but occasionally bleeding is severe.
Temporary liver inflammation (hepatitis) and diarrhea may occur during an infection.
Subacute sclerosing panencephalitis is a rare complication of measles that causes brain damage and death often over years of progressive brain deterioration.
In healthy, well-nourished children, measles is usually not serious. However, even in the United States, about 2 in 1,000 children infected with measles die. The risk of death is much higher in the developing world, where there are about 110,000 mainly in children. Undernutrition and vitamin A deficiency may increase the risk of death in people infected with measles.
Measles vaccine, one of the routine immunizations of childhood, is given between 12 and 15 months of age but can be given to children as young as 6 months during a measles outbreak or before international travel. A second dose is given between 4 years and 6 years of age. Children who were less than 1 year of age when immunized still need 2 doses after their first birthday. The vaccine that is used is a combined vaccine. The combination contains measles, mumps, and rubella (MMR) vaccines and sometimes also varicella (chickenpox) vaccine. There is no longer a separate vaccine just for measles. In some children, the vaccination causes mild fever and a rash, but people are not contagious. The vaccine does not cause autism (see MMR vaccine and autism).
Children (and adults) who are exposed to measles and do not have immunity may be protected by vaccination within 3 days of exposure. People who should not receive the vaccine, such as pregnant women, people with certain cancers or untreated tuberculosis, and people with serious illnesses or weakened immune systems, instead are given immune globulin for protection when they are exposed to measles.
There is no specific treatment for measles. Doctors give vitamin A to children with measles, because vitamin A has been shown to reduce the number of deaths and serious disease resulting from measles in countries where vitamin A deficiency is common.
Children with measles are kept warm and comfortable.
Acetaminophen or ibuprofen may be given to reduce fever.
If a bacterial infection develops, an antibiotic is given.