Babies rash

Siobhan

So my LO is a little chunky monkey (6months.. 15pounds) and sometimes she sweats here in FL with how hott our freaken humidity gets.. but lately I've noticed that she has a rash under her chin. I thought it maybe was eczema and tried using Baby Aveeno eczema wash and lotion but it hasn't gone away yet so I went to Wal-Mart to check out some rash creams for babies and literally saw nothing,!!😧 What are your thoughts and ideas mama's?