From my quick Google searching it seems that scorpion venom can have similar reactions as bee (or other stinging insects). I was stung by a wasp on Friday, perhaps maybe the fifth time in my life I’ve been stung by something. However, it was the first time I had a serious reaction to it. In 15 mins I had turned as red as a ripe strawberry and was having numbness in my leg, face, and mouth. Not to mention a break out of full body hives.
I managed to get a large dose of Benadryl about a half hour after the initial sting, which seemed to keep the symptoms from progressing. Due to some things going on with my parents I learned that anger and stress seem to release a good bit of chemicals that stimulate blood pressure and inhibit the reaction…
It’s now 3 days later and my leg is still somewhat swollen. I can easily see how a sting to the testicles could do some damage if the swelling was intense and presistent.