The symptoms of measles usually appear 10-12 days after infection, and last for 7-10 days. A person with measles is considered contagious as early as 4 days before symptoms appear, and up to 4 days after the characteristic rash has appeared.
Measles typically begin with a high fever, cough, runny nose, and red, watery eyes (conjunctivitis). As such, the start of a measles infection can be easily confused with any other upper respiratory tract infection (cough and colds).
2-3 days after the start of symptoms, distinct white spots called Koplik spots can appear inside the mouth. These spots do not always appear, but when they do, one can be sure that the individual has a measles infection.
3-5 days after the start of symptoms, the distinctive rash--flat red spots with small red bumps--appears. The rash usually starts behind the ears and the hairline, and gradually spreads downwards, from the face to the neck, trunk, legs, and feet to cover most of the body. The rash may be itchy and can coincide with a high fever.
After that, the symptoms will start to resolve.