Rubella
Rubella - commonly known as German measles or 3-day measles - is an infection that primarily affects the skin and lymph nodes. It is caused by the rubella virus (not the same virus that causes measles), which is usually transmitted by secretions from the nose or throat. It can also pass through a pregnant woman's bloodstream to infect her unborn child. As this is a generally mild disease in children, the primary medical danger of rubella is the infection of pregnant women, which may cause congenital rubella syndrome in developing babies.
Rubella infection may begin with 1 or 2 days of mild fever (99 to 100 degrees Fahrenheit, or 37.2 to 37.8 degrees Celsius) and swollen, tender lymph nodes, usually in the back of the neck or behind the ears. On the second or third day, a rash appears that begins on the face and spreads downward. As it spreads down the body, it usually clears on the face. This rash is often the first sign of illness that a parent notices.
More
http://dir.yahoo.com/Health/Diseases_and_Conditions/Rubella/
http://www.lib.uiowa.edu/hardin/md/rubella.html