Thanks for this. I had heard of it but not ever thought to look at pictures of what it looks like. I've done that now and realise how easy it would be to miss it. In the extreme cases and possibly later stages, yes you'd notice something but one pic just showed a tiny rash under the breast that didn't look like much except the heat rash some women of larger boobage get under there (or rub rash from bra).
Interesting to look and learn about it. Thanks again for the link.