I think the toxin is so mild that unless you have allergies already, most people are unlikely to react...
You might still get an infection because when you get stabbed byt their pectoral fins, the skin comes off their fin (which is a hard sharp cartilage/bone) and embeds in your skin... pretty gross, generally peoples bodies push it back out or break it down, same as a splinter.
I have a fish allergy (ironically!) and have had this happen several times, unfortunately it seems to be getting worse each time.
Saying that, the last one was a dead cory i didnt know was there, stabbed me and within 10 minutes my arm was swollen and so was my throat, tho only slightly, luckily my automatic reaction was to run my hand under hot water, as hot as i could tolerate and take 2 piriton tablets. Kept it under control, though was really sick... everywhere lol.
I have had same reaction to synodontis and pictus catfish too...
The worst was an unknown marine invert, thought to be a red spidery crab thing (found afterwards)...
That had me in a+e and really very sick and what, 4-5 months later it still aches and i now have a far worse reaction in that hand, like i cant handle frozen foods like prawn or krill or mysis etc in my right hand as swelling is almost instant... my left hand doesnt react LOL.
Ahhh love working in the aquatics trade, every day fraught with danger