I spent this past weekend working on DIY-ing luminaries for my centerpieces/favors. This involved spray painting, and I went through about 2.5 cans, so lots of spraying. I noticed that my finger hurt afterwards, but I assumed it was skin irritation from pushing the button so hard. 4 days later and my fingertip still feels numb, like when your hand falls asleep or you've been to the dentist.
I started panicking, thinking I'd possibly given myself permanent nerve damage in that finger. It was really scary because I'm a professional musician, and I was afraid I'd thrown away my whole career over a wedding DIY that wasn't even necessary.
After some googling, it seems this is an extremely common problem with spray paint cans - so much so that they sell some sort of trigger adapter to avoid compressing the nerve.
From what I've read, most people notice improvement after about 3 months, and some people have said that after a year or so, they have all feeling back. Phew. But still scary.