K.M.
Push on the "rash" area and see if it blances (i think is the term) but basically if you push it and the skin turns white/changes color you can hold off until tomorrow am but if it stays red then call the Dr's 24hr line and advise them of this you may need to go to the ER. This is the "rash" advice given to me by my pedi when my son broke out for the first time we still do not know what caused it but it cleared up in 24hrs.