Measles is a disease which usually produces fever, cough , conjunctivitis ("pink eye", but not quite the same as the "pink eye" seen with colds and earaches), a red, bumpy rash, and a rash ("Koplik spots") inside the cheeks. The measles virus affects only primates (humans, as well as monkeys and similar species); it does not affect animals.
It takes 1-1/2 to 2 weeks after exposure before someone develops the initial signs of infection, which include fever (which starts low but increases, sometimes to as high as 105 F) followed by cough, runny nose, and conjunctivitis (pink eye). The rash can appear anywhere from 1 to 7 days (but usually 2-4 days) after the "prodrome" (the fever and other initial signs of infection); it usually starts at the patient's hairline, then spreads to the face and neck and from there to the rest of the body, finally reaching the hands and feet, and then fades with the oldest rash lesions disappearing first. Koplik spots are tiny blue-white spots which appear up to 2 days before or after the rash shows up. Measles infection can also cause loss of appetite, swelling of lymph nodes, and diarrhea (which is more common in babies with measles). It can be complicated by secondary ear infections, croup, and pneumonia.
In some cases (about 1 out of 1,000) patients with measles develop inflammation of the brain tissue, or "encephalitis". Very rarely, a persistent rubeola infection can produce SSPE, a disease in which nerves and brain tissue degenerate (sometimes many years after the original case of measles); now that we vaccinate most children against measles, SSPE is almost never seen. Up to 6% of patients with measles develop pneumonia, which can be either viral (from the measles virus) or bacterial, and this is the most common cause of death from measles (60% of deaths; acute encephalitis causes another 15% of measles-related deaths, while SSPE is responsible for death in only 5 to 10 of every 1 million cases of measles).
Before the vaccine came along, measles epidemics occurred about every 2 years, usually in winter and early spring when unimmune children were together in school, and most measles patients were preschoolers and young elementary-school kids. Nowadays most cases are seen in unvaccinated children (kids younger than 15 months who haven't had the vaccine yet, and preschool kids who should have had the vaccine but haven't) and older children -- some in college -- who received one dose of vaccine but did not become immune as a result. Measles outbreaks in the United States occur only in people -- children or adults -- who were never vaccinated and are still susceptible to measles infection,, or in those people who do not become immune after vaccination. Up to 5% of children who get a single dose of vaccine will not become immune: because of this we now give a second dose of vaccine to all children, usually when they start kindergarten. Measles immune globulin is available and can prevent measles, or at least make it milder than it otherwise would be, if it is given to someone who isn't yet immune within 6 days of exposure.
There are no antibiotics available for treatment of measles. Children who are deficient in vitamin A seem to be more likely to have severe measles (and more likely to die from the infection) than are children with enough vitamin A; therefore the World Health Organization and UNICEF recommend giving 1 to 3 doses of vitamin A to children older than 6 months who have measles and are hospitalized because of measles or its complications or who are malnourished, have immune system problems, or who are proven to have a vitamin A deficiency. Since vitamin A can be toxic in excessive doses, the supplement should only be given on the advice of the child's doctor. Antibacterial antibiotics can be used to treat bacterial pneumonia occuring during a measles infection.
Rubella is a pretty benign disease as viral diseases go: your symptoms usually include a red, bumpy rash, swollen lymph nodes (most often around the ears and neck), and a mild fever; some people also feel achy for a little while. Adolescents and adults, especially women, are much more likely than children to have muscle and joint aches with rubella, but these go away fairly quickly. (It is also possible to have rubella encephalitis, but this is rare.) It takes around 2 to 3-1/2 weeks after exposure to develop rubella. The rubella virus is not related to the rubeola virus, and being immune to one kind of measles does not make you immune to the other kind.
Unfortunately, if a woman has rubella during the first 3-4 months of her pregnancy, the virus can induce many different birth defects, some of which are quite severe. Among the defects doctors have seen in "congenital rubella" are eye defects (cataracts, glaucoma, and "microphthalmia" (small non-functional eyes) ), heart problems (defects of the wall between the two sides of the heart, narrowing of the arteries to the lungs, and an open duct bypassing the lungs), ear problems (deafness caused by defects in the nerves and sound sensing organs), and neurologic problems (including mental retardation) -- among others. For that reason, obstetricians test every pregnant woman to make sure that she is immune to rubella, and we try to immunize every child to the virus. A single dose of the vaccine usually gives lifelong protection; we usually give two doses (as the combined measles-mumps-rubella, or "MMR", vaccine) to be sure that every child is immune. This helps protect non-immune pregnant women too, by reducing the chances of their being exposed to rubella by sick children. Rubella immune globulin is available and can help decrease the symptoms of rubella, but does not necessarily prevent infection and birth defects in the developing baby: there have been babies born with congenital rubella to mothers who received rubella immune globulin shortly after being exposed to rubella.
We now have a single vaccine that protects against measles, mumps, rubella, and chickenpox. This vaccine, known as "MMRV", is given at the same time as the MMR vaccine is usually given (at age 12-18 months and at age 4-5 years). It appears in trials to work just as well as the separate MMR and chickenpox vaccines, and means fewer needle pokes for a child (which I certainly would have been in favour of when I was that age...). For more information, ask your child's doctor.