Hey Molly !
Read your post and the funny thing is that one of the reasons why my rash would come and go (which would confuse me more) was because I would alternate the new bras with the older ones (which happend to be made in Sri Lanka, Thailand and Israel). So while those weren't giving me the rash, the newer ones (Made in China) would cause the flare-up all over again...
I would just stay away from ANY brand that's made in China, that's where the problem is stemming from..
Bad dog food, lead in toys, Bad Bras !!