I had this issue several years ago. I was getting contact dermatitis from deodorant. Using hydrocortisone cream etc. Anyway I had to switch to my own home meds deodorant with bicarb, cornflour and coconut oil plus a few drops of essential lemon oil for a nice fragrance. This worked for ages then I became sensitive to that and had to stop using it. The only deodorant I could then use was bionsen aluminium free. I've used that for a few years now, but all of a sudden I'm sensitive to that now too. I've tried pretty much everything. The mineral water ones, sprays, roll ons, home made.
I work in a nursing home which is hot and sweaty, and whilst I wash regularly I don't feel brave enough to go completely without deodorant. I'm trying to go without it, and just nipping to the toilet every now and then to have a quick freshen up wash under my arm pits, and whilst I'm not smelling, I am really conscious that maybe I am. I shower every evening and have a good flannel wash every morning. So it's not that I'm dirty. I'm just really sensitive to deodorant. What on Earth can I do!?