Measles is an acute, highly contagious viral infectious disease. The thought of measles may bring to mind the red, blotchy rash that often accompanies this disorder. But the rash is just an outward sign of the more significant changes happening inside the body - especially within the respiratory system.

Measles is primarily a respiratory infection caused by a highly contagious virus found all over the world. Also called rubeola, measles can be serious and even fatal for small children.

Thanks to the vaccine, less than 100 cases of measles occur each year.

So why do we still vaccinate against measles when the disease is so rare? Because measles is more common in other countries. Approximately 30 million cases of measles occur worldwide each year, resulting in the deaths of one million children. The disease can be brought by international travelers and visitors to our country. If we weren't protected, a measles epidemic could result.

Signs and symptoms

Usually signs and symptoms of the disease appear 10 to 12 days after exposure to the virus. They may include:

• Fever

• Dry cough

• Runny nose

• Inflamed eyes (conjunctivitis)

• Sore throat

• Muscle pain

• Sensitivity to light

• Tiny red spots with bluish-white centers on the inner lining of the cheek, called Koplik's spots

• Enlarged lymph nodes

• Abdominal pain

• A rash made up of large, flat, red-to-brown blotches that often flow into one another, usually appearing two to four days after the earliest symptoms start

Measles typically begins with a mild to moderate fever, accompanied by other signs and symptoms such as a persistent cough, runny nose, inflamed eyes (conjunctivitis) and sore throat. Two or three days later, Koplik's spots — a characteristic sign of measles — appear. Then the fever spikes, often as high as 104 or 105 F, at the same time a red blotchy rash surfaces on the face, along the hairline and behind the ears. This slightly itchy rash rapidly spreads downward to the chest and back and, finally, to the thighs and feet. After about a week, the rash fades in the same sequence that it appeared.

Measles causes a red, blotchy rash that first appears on the face and behind the ears, then spreads downward to the chest and back and finally to the feet....

Causes

The cause of measles is a virus that's contagious from four days before to four days after the rash appears. Measles is so contagious that if one person has the virus, 90 percent of their susceptible close contacts also will become infected.

The virus exists in the mucus in the nose and throat of an infected child or adult. When that person coughs, sneezes or talks, infected droplets spray into the air, where other people can inhale them. The infected droplets may also land on a surface where they remain active and contagious for two hours. The virus spreads when someone puts their fingers into their mouth or nose after touching the infected surface. You can even get measles just by being in the same room with an infected person.

Once the virus gets inside the body, it typically grows in the cells that line the back of the throat and lungs. The infection then spreads throughout the body, including the respiratory system and the skin.

Risk factors

Measles is highly contagious. Any exposure to an infected person may cause the infection if you aren't immune to the disease. Measles is extremely rare because most people are vaccinated against the infection at an early age.

If you've already had measles, your body has built up its immune system to fight the infection, and you can't get measles again. If you were born or living before 1957, you're probably immune from measles, even if you never had the vaccine. You lived through several years of measles epidemics and were likely infected naturally by the measles virus without developing symptoms, and consequently may have acquired immunity.

Measles is more common in other countries, and the disease is particularly severe in people with vitamin A deficiency, which may be part of malnutrition in Third World countries. This is something to consider before traveling abroad.

When to seek medical advice

Contact your doctor if you think you or your child may have been exposed to measles, or if you or your child exhibits some of the symptoms that make you suspect measles. Remember: Most childhood rashes won't actually be measles, but cases of measles still do occur.

Also be sure to review your child's immunization records with your doctor, especially before starting grade school, before college and before international travel.

Screening and diagnosis

Your doctor can usually diagnose measles based on the disease's characteristic rash as well as the small, bright red spots with bluish-white centers on the inside lining of the cheek, called Koplik's spots. Because measles is so uncommon today, your doctor may obtain a blood sample to confirm whether the rash is truly measles.

Complications

Measles usually lasts about 10 to 14 days. People with measles may become quite ill, but most people recover completely. Complications are more common in adults and in children under age 5 and may include:

• Ear infection. Measles causes an ear infection in nearly one out of every 10 children.

• Encephalitis. About one in 1,000 people with measles develops encephalitis, an inflammation of the brain caused by a viral infection, which may cause vomiting, convulsions and, rarely, coma. Encephalitis can closely follow measles, or it can occur years later during adolescence as a result of a slow virus infection. The late form, called Dawson's encephalitis, is rare.

• Pneumonia. As many as one out of 20 children with measles gets pneumonia, which can be life-threatening.

• Diarrhea or vomiting. These complications are more common in infants and small children.

• Bronchitis, laryngitis or croup. Measles may lead to inflammation of your voice box (larynx) or inflammation of the inner walls that line the main air passageways of your lungs (bronchial tubes).

• Pregnancy problems. Pregnant women need to take special care to avoid measles, because the disease can cause miscarriage, premature labor or babies with low birth weights.

• Low platelet count (thrombocytopenia). Measles may lead to a decrease in platelets — the type of white blood cells that are essential for blood clotting.

Treatment

No treatment can get rid of measles. However, nonimmunized children and adults may be given the measles vaccination within 72 hours of exposure to the measles virus, to provide protection against the disease. Pregnant women, infants and people with weakened immune systems who are exposed to the virus may also receive an injection of proteins (antibodies) that can fight off infection, called gamma globulin. When given within six days of exposure to the virus, these antibodies can prevent measles or make symptoms less severe.

You or your child may also take over-the-counter medications such as acetaminophen (Tylenol, others) or nonsteroidal anti-inflammatory drugs (NSAIDs) to help relieve the fever that accompanies the virus. Don't give aspirin to children because of the risk of Reye's syndrome — a rare, but potentially fatal disease.

If you develop a bacterial infection such as pneumonia or an ear infection, your doctor may prescribe an antibiotic. Young children or people with impaired immunity who are hospitalized with severe measles might also benefit from prescription doses of vitamin A.

Isolation is another element of treatment. Because measles is highly contagious from about four days before to four days after the rash breaks out, people with measles shouldn't return to activities in which they interact with other people during this period. It may also be necessary to keep nonimmunized people — siblings, for example — out of the infected person's house. Talk with your doctor about keeping someone with measles isolated.

Prevention

The measles vaccine is extremely effective. Before this vaccine. Widespread use of the vaccine has reduced the number of measles cases in this country by more than 99 percent. In fact, since the late 1980s — when there was a slight jump in measles cases and deaths, partly because kids weren't getting vaccines — health care professionals have stepped up immunization programs, and the number of measles cases has dropped to an all-time low.

The measles vaccine is usually given as a combined measles-mumps-rubella (MMR) inoculation, which contains the safest and most effective form of each vaccine. It's made by taking the measles virus from the throat of an infected person and adapting it to grow in chick-embryo cells in a lab. When this modified measles virus is given to a child as part of the MMR vaccine, the virus grows and causes a harmless infection before the immune system gets rid of it. This harmless infection causes 95 percent of children to develop lifetime immunity to the virus. But a second dose of the vaccine is recommended to protect the 5 percent who didn't develop immunity after the first dose and to boost immunity in the 95 percent who did.

Doctors recommend that children receive the MMR vaccine between 12 and 15 months of age, and again between 3 and 6 years of age — before entering school. Usually babies are protected from measles for six to eight months after birth because of the immunity passed on from their mothers. However, if a child requires protection from measles before 12 months of age — for example, for certain foreign travel — the vaccine can be given as early as 6 months of age. The vaccine may also be given to nonimmunized individuals who are exposed to the virus.

Do you need the MMR vaccine?
You don't need a vaccine if you:

• Had two doses of the MMR vaccine after 12 months of age or one dose of the MMR vaccine plus a second dose of measles vaccine

• Have blood tests that prove you're immune to measles, mumps and rubella

• Are a man who was born before 1957

• Are a woman who was born before 1957 and you don't plan to have any more children, you already had the rubella vaccine or you have a positive rubella test

You should get a vaccine if you don't fit the criteria listed above and you:

• Are a nonpregnant woman of childbearing age

• Attend college, trade school or postsecondary school

• Work in a hospital, medical facility, child-care center or school

• Plan to travel overseas or take a cruise

The vaccine is not recommended for:

• Pregnant women or women who plan to get pregnant within the next four weeks

• People who have had a life-threatening allergic reaction to gelatin or the antibiotic neomycin

If you have cancer, a blood disorder or another disease that affects your immune system, talk to your doctor before getting an MMR vaccine.

Side effects of the vaccine
You can't get measles from the MMR vaccine, and most people experience no side effects from the vaccine. About 10 percent of people develop a fever between five and twelve days after the vaccination, and about 5 percent of people develop a mild rash. Fewer than one out of a million doses causes a serious allergic reaction.

It was once commonly believed that people who were allergic to eggs couldn't receive vaccines grown in chick embryos, such as the measles vaccine. But this isn't true. People with allergies to eggs can safely receive the measles vaccine as well as the combined MMR vaccine.

In recent years, some news reports have raised concerns about a connection between the MMR vaccine and autism. However, extensive reports from the American Academy of Pediatrics, the Institute of Medicine, and CDC conclude that there's no scientifically proven link between the MMR vaccine and autism. In addition, there's no scientific benefit to separating the vaccines. These organizations note that autism is often identified in toddlers between the ages of 18 months and 30 months, which happens to be about the time children are given their first MMR vaccine. But this coincidence in timing shouldn't be mistaken for a cause-and-effect relationship.

Self-care

If you have measles, keep in close contact with your doctor as you monitor the progress of the disease, and watch for complications. Also try these comfort measures:

• Rest and avoid busy activities.

• Drink plenty of water, fruit juice and tea to replace fluids lost by fever and sweating.

• Wipe red eyes frequently with a clean, wet cotton ball.

• For respiratory relief, take a cough medicine and use a humidifier.

• If you or your child finds bright light bothersome, as do many people with measles, keep the lights low or wear sunglasses — even while sleeping. Also, avoid reading or watching television. Light from a reading lamp or from the television may be bothersome.