Measles is a highly contagious viral illness. It was first described in the 7th century. During the prevaccination era there was nearly universal infection during childhood. the incubation period of measles, from exposure to prodrome averages 10-12 days. From exposure to rash onset averages 14 days. The prodrome lasts 2-4 days (range 1-7 days). it is characterized by fever, followed by cough, coryza (runny nose), and/or conjunctivitis.
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