hi doc

i started getting this itchy ,flakey spots around my breat area,after a while it went away but left brown spots mark on my skin,now the same thing has come around my neck area..but not all over my neck just on the side of my neck spreading on my face..

its very itchy sometimes and gets very red when exposed to heat and sweat...what is it and what do i do??

i am 24 yrs old,i am not under any medication..and oh its bben there for about a month now..

please help