Measles is also known as rubeola. Measles is a highly contagious disease that’s caused by an RNA virus that changes constantly. Symptoms of Measles usually include red eyes, sneezing, runny nose, very high fever and sensitivity to light, and it affects the respitory system. This disease is best known for the rash it causes. It is probably the most deadly known of all childhood illnesses. It is caused by the measles virus, and grows in cells in the throat and lungs.