Toddler Acute Rash is generally contagious. Emergency rash in toddlers is a viral infection that is contagious and is mainly associated with human herpes virus type 6 infection. The source of human herpesvirus type 6 infection may be primarily a child with this viral infection. It may be transmitted in a number of ways, but the main route of transmission is horizontal transmission through saliva. Childhood rash often begins with a high fever, and then the fever goes down and the rash comes out. It is usually a sudden onset of a high fever for 3 to 5 days, and after the fever goes down, a large number of congestive maculopapular rashes may appear all over the body of the child, and the rash usually lasts for 2 to 3 days, and during the period of the rash there may be a slight feeling of malaise. It is important to note that toddlers are contagious from the time the fever rises to the time the rash subsides, and will be less contagious until at least 3 days after the rash subsides. If your baby has emergency rash, seek medical attention.