Symptoms and Complications
For one or two weeks after an infection, the virus multiplies without causing
any symptoms. This is called the incubation period. After that, symptoms
such as cough, fever, runny nose, and red eyes will appear. Children may also
become irritable. Within four days, a rash (large brown or red blotches) may
develop behind the ears, and perhaps on the forehead and face, and can spread
to the trunk, arms, and legs. The rash usually begins to fade within five days,
often starting at the top (head) before it clears up in the lower parts of the
body (legs). Once the rash has completely disappeared, the skin may appear a
bit brownish and the top skin layers may peel off soon afterwards.
The rash isn't painful, though it may itch a bit. Some people may experience
increased sensitivity to light, and their eyes may become red and inflamed.
During the peak of the infection, a fever may develop with a body temperature
as high as 104°F.
Measles is contagious for about four days before the rash appears and about
five days afterwards. It's best for people with measles to stay away from
others so they won't get infected.
Measles usually runs a simple course with few complications, but in certain
cases, problems can arise. The most common complication is pneumonia, a
bacterial infection of the lungs. This is because bacteria have an easier time
infecting a body that's already been attacked by a virus. The signs of a bacterial
infection include a severe cough that lasts for more than five days and yellowish
or greenish sputum. If these symptoms develop, a doctor should be consulted
right away. A second common bacterial infection that occurs as a result of tissue
inflammation caused by the measles virus is a middle ear infection (otitis
media).
In about 1 case in 1500, the virus can enter the brain, causing encephalitis.
This usually happens during the late stages of infection, once the rash has
already developed. Unfortunately, there's no cure, but some patients may recover
on their own without any further problems.
In a small number of patients, the virus can take permanent rest in the brain
and be awakened years later to cause re-infection and brain damage. This results
in a condition called subacute sclerosing panencephalitis (SSPE), which
is often fatal. This is very rare, occurring in about 14 out of every million
cases of measles.
Pregnant women who catch measles have a greater risk of miscarriage or birth
defects.