be4 ayear i had the same thn in my shoulder and nick 2,and i went 2 the doctor and he said thats caz my skin is too sensetive and maybe i have weared some dirty cloths or not well cleaned,and he asked me 2 wash them more and after every time i wear them,and not 2 let my sisters wear them caz my skin cant deal with that any way now its gone and he gave me amedicin 2 put it on that spots,so its not big deal,just ask a doc 4 some medicin 4 ur baby i hope i helped y,and gd luck 4 u both u+ur baby,bye