By Wand Agency
Fifth's disease is a mild illness caused by a virus known as human parvovirus B19. The medical name for fifth's disease is erythema infectiosum (EI). It is seen primarily in school-aged children between 5 and 14 years of age during the spring and winter. Fifth's disease causes a reddish rash on the child's face so that it looks as if the child has been slapped on both cheeks.