Toddler rash is not something that every child gets because the cause of it is due to a viral infection that the child suffers from. This is due to the fact that every child is different and some children get antibodies from their mothers. Therefore, it is a very small percentage of children who get it, and most children do not get it if they are healthy and well cared for. After a child has had measles, the child will often develop a fever and even encephalitis. In most cases, the fever drops suddenly within 3-4 days of the onset of the disease, but a small rash develops all over the body. This is a typical manifestation of infantile emergency, but infantile emergency is relatively harmless to children and not every child will get it.