My 21 Month Old Daughter Has Reoccurring Small Red Splotchy

My 21 month old daughter has reoccurring small red splotchy rash (usually dime to nickel size spots) show up on her legs.. Inner thighs, calves, and now on hamstring/buttock. They don't seem to bother her daily.. But I tried to put lotion on it and she cried as it must have burned. They usually last about 2 weeks.
Should I take her to her pediatrician to be examined as they are present now again.