Maybe try waxing your underarms. I used to get bumps and irritated in general everytime I'd shave. I LOVE the results from waxing, smooth, REALLY hairless and it does last much longer. You do have to have a bit of length of the hair to wax again, which is a bit of a bummer, but the hairs grow in much finer. Go to a professional for the first time, but it is a bit too spendy for me, so I have my own kit (from Sally's) now that my husband helps me with. I can't get the right angle and tightness of skin to wax them by myself, but I do know of other women that do, they use the kits available from like Target.