Rash on my son's chin?

My son keeps getting a rash on his chin and we can't pinpoint what is causing it. We notice that it gets most intense after he eats. At first we thought it was specific foods but it seems to happen with pretty much any food. He is also teething so when he eats he drools a lot. Could it be a drool rash? It is red with little raised spots and when he isn't eating it really isn't noticeable.