Measles (Rubeola)

Measles (ME-zuls) is a viral respiratory system * infection best known for the rash of flat, red blotches that appear on the arms, face, neck, and body.

Measles, also known as rubeola (roo-be-O-luh), is a highly contagious * viral infection caused by the measles virus. Most people are familiar with its best-known feature: a near full-body rash of red blotches. In fact, measles is primarily an infection of the respiratory system. The disease has been diagnosed throughout the world; before a vaccine * was available, it commonly appeared in the United States in springtime epidemics * every few years. In the United States, 1 to 2 deaths occur for every 1,000 cases of measles. In developing countries, the fatality rate can be as high as one in every four people who contract the disease. Most deaths from measles in the United States are caused by pneumonia * , either from the measles virus itself or from a bacterial infection that arises as a complication of measles.

Measles in the developing world remains a serious problem today. Worldwide, about 20 million people get measles each year; about 96,000 die, down from 545,000 deaths per year worldwide in 1990. Immigrants to the United States who had not received the vaccine in their native countries account for the majority of cases of the disease in the United States.

Measles is highly contagious and can spread quickly among people who have not been immunized against it. The measles virus spreads by direct contact with an infected person or by breathing in tiny droplets of fluid sent into the air when the person sneezes, coughs, or laughs. A cough or sneeze releases thousands of microscopic particles that contain the virus. These particles can stay in the air, able to infect people, for up to two hours. In some cases, people have caught measles after entering a room that an infected person had already left. A person with measles is contagious from one to two days before the symptoms begin until four or five days after the rash appears.

After a person has been exposed to the virus, there is an incubation period that averages 10 to 12 days. The first symptoms include fever, runny nose, cough, and reddened eyes that are sensitive to light. Koplik spots, a unique sign of measles, break out one to two days before the rash begins and usually are gone by the time it appears; they are bluish-white dots found on the inside of the cheeks and other places on the mucous membranes (moist tissues) in the mouth.

The measles rash typically begins on the forehead and extends across the face, neck, and body. It generally takes several days for the rash to travel from head to toes. The red blotches often spread out and join, completely covering the skin, especially on the face and shoulders. Once the rash appears, two to four days after the onset of illness, the fever rises and may peak at 104 to 105°F. During this time, the patient looks and feels very ill. Symptoms improve soon after the rash has traveled down to the legs and feet, usually accompanied by a rapid drop in temperature. The rash fades along the same path that it appeared, beginning at the forehead and working its way down. As the rash disappears, the skin may temporarily look brown, dry, and flaky. Other symptoms of measles include loss of appetite, vomiting, and diarrhea (dye-uh-REE-uh), especially in young children. Hemorrhagic (HEH-muh-rij-ik) measles is a rare and serious form of the disease characterized by hemorrhaging (uncontrolled or abnormal bleeding), high fever, seizures * , and delirium * .

Measles can be diagnosed by asking the patient about symptoms and performing a physical examination. If there is a question about the diagnosis or if it is necessary to confirm a suspected case of measles, blood tests can determine whether antibodies * to the virus have developed in the body.

Because measles is caused by a virus, treatment generally is aimed at keeping the patient comfortable until the infection runs its course. The high fever and sweating that accompany measles raise the risk of dehydration * , so patients should have plenty of rest and fluids. Taking vitamin A may aid recovery in some cases, especially among children with poor nutrition. Serious cases may require a hospital stay and intravenous * fluids. Antibiotics are given when bacterial infections (such as ear infections or pneumonia) develop as complications of the disease.

Measles generally lasts between 10 and 14 days from the onset of symptoms through the fading of the rash. Ear infections, croup * , and pneumonia sometimes accompany measles. Less commonly, inflammation of the brain (known as encephalitis, en-seh-fuh-LYE-tis) or inflammation of the heart muscle (known as myocarditis, my-oh-kar-DYE-tis) can occur. Subacute sclerosing panencephalitis * (SSPE), a type of encephalitis, is an extremely rare late complication of lasting measles virus infection that can cause gradual loss of brain function. SSPE may occur months, years, or even decades after measles infection, but it is almost never seen in the United States as a result of widespread use of the measles vaccine. If a pregnant woman contracts measles, the infection can harm her developing baby, leading to miscarriage * , premature labor * , or low birth weight.

The best protection against measles is immunization. The vaccine usually is given as part of a combined measles-mumps-rubella (MMR) vaccine that children typically receive twice in their lives. The first round is given when an infant is 12 to 15 months old, and the second when the child is ready to start school, at four to five years of age. Children also may receive the second vaccine when they are 11 or 12 years old if they did not receive it earlier. Because about 5 percent of people do not develop protective antibodies after the first MMR vaccine, the second dose offers better protection against infection. If someone comes into contact with a person who has measles and then is vaccinated within three days of that exposure, the vaccine may prevent or lessen the severity of a case of measles. Immune globulin * can have the same result if it is given within six days of exposure to the virus.

See also Encephalitis • German Measles (Rubella) • Mumps • Myocarditis and Pericarditis • Pneumonia • Vaccines and Immunization • Viral Infections

* respiratory system, also called the respiratory tract, includes the nose, mouth, throat, and lungs. It is the pathway through which air and gases are transported down into the lungs and then released from the body.

* contagious (kon-TAY-jus) means transmissible from one person to another, usually referring to an infection.

* vaccine (vak-SEEN) is a preparation of killed or weakened germs, or a part of a germ or product it produces, given to prevent or lessen the severity of disease if a person is exposed to the germ itself. Use of vaccines for this purpose is called immunization.

* epidemics (eh-pih-DEH-miks) are outbreaks of diseases, especially infectious diseases, in which the number of cases suddenly becomes far greater than usual. Usually epidemics are outbreaks of diseases in specific regions, whereas widespread epidemics are called pandemics.

* pneumonia (nu-MO-nyah) is inflammation of the lungs.

* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.

* dehydration (dee-hi-DRAY-shun) is a condition in which the body is depleted of water, usually caused by excessive and unreplaced loss of body fluids, such as through sweating, vomiting, or diarrhea.

* intravenous (in-tra-VEE-nus), or IV, means within or through a vein. For example, medications, fluid, or other substances can be given through a needle or soft tube inserted through the skin's surface directly into a vein.

* delirium (dih-LEER-e-um) is a condition in which a person is confused, is unable to think clearly, and has a reduced level of consciousness.

* seizures (SEE-zhurs), also called convulsions, are sudden bursts of disorganized electrical activity that interrupt the normal functioning of the brain, often leading to uncontrolled movements in the body and sometimes a temporary change in consciousness.

* croup (KROOP) is an infection involving the trachea (windpipe) and larynx (voice box) that typically occurs in childhood. It causes inflammation and narrowing of the upper airway, sometimes making it difficult to breathe. The characteristic symptom of croup is a barking cough.

* subacute sclerosing panencephalitis (sub-uh-KYOOT skluhRO-sing pan-en-seh-fuh-LYE-tis), or SSPE, is a chronic brain disease of children and adolescents that occurs months or years after having had measles; it causes convulsions, movement problems, and intellectual disability, and is usually fatal.

* miscarriage (MIS-kare-ij) is the end of a pregnancy through the death of the embryo or fetus before birth.

* premature labor is labor (the birth process) that begins too early, before the fetus has developed fully in the womb.

* immune globulin (ih-MYOON GLAH-byoo-lin), also called gamma globulin, is the protein material that contains antibodies.