Sounds like they had a DeQuervain’s injection (if it’s intratendinous instead of just under the tendon sheath there can be a lot of resistance…especially if using a tuberculin syringe/needle), and then had either a trigger thumb injection or an intraarticular injection of the 1st carpometacarpal joint. Either way, they shouldn’t have had “nerve damage” from either injection. The “nerve damage” was probably already there. Without a pre- and post-injection EMG/NCS, it’s impossible to know for sure. The skin atrophy and other signs can be relatively common with kenalog and other insoluble steroids. I don’t what the “thumb locking” is unless the patient means trigger thumb. Some physicians will use sterile saline injections in the atrophied area to speed up the recovery.
Kenalog in blood - Derby et al. "Size and aggregation of corticosteroids used for epidural injections"
BlackBerry thumb is a neologism that refers to a form of repetitive strain injury (RSI) caused by the frequent use of the thumbs to press buttons on PDAs , smartphones , or other mobile devices . The name of the condition comes from the BlackBerry , a brand of smartphone that debuted in 1999,  although there are numerous other similar eponymous conditions that exist such as " Wiiitis ",  " Nintendinitis ",  "Playstation thumb", "texting thumb",  "cellphone thumb",  "smartphone thumb", "Android thumb", and "iPhone thumb". The medical name for the condition is De Quervain syndrome and is associated with the tendons connected to the thumb through the wrist. Causes for the condition extend beyond smartphones and gaming consoles to include activities like golf, racket sports, and lifting.