horrible rash/spots on 2 year old chin

[caspered]

Ok not a major health worry but DD just turned 2 and has developed an awful rash/set of spots on chin for the past 3 weeks. She does suck her thumb and is obsessed with drinking juice out of a bottle. I have diluted the juice to practically nothing, she has really stopped sucking her thumb during the day; and I have tried to be meticulous about keeping her chin clean and dry but it is not working. Any handy hints?

DS had very sore skin on his chin I went to the pharmasist and they gave me DiproBase ointment, it was because he was quite a dribbler and I think the central heating dried his skin. The DiproBase keeps the moisture away from the skin.

Hope this helps, maybe someone will have better ideas.