For me even a single corticosteroid injection in my hand gave me a largish spike and kept my levels up much higher for several days after. I wondered what the hell was going on until I remembered seeing info about steroids and glucose levels.
Interestingly though, my long term corticosteroid eye drops (dexamethasone) apparently wouldn't/shouldn't (and didn't!) have any similar effects...
I can't quickly find the link now to the original info I found on Google regarding both instances, but
https://www.drugs.com/ has detailed information about drugs their side effects and interactions.
Robbity