In BC we sometimes have lots of stinging yellow jackets. Some folks are highly allergic to these nasty stings.
One of the wilderness first aid treatments used for allergic/anaphalactic responses to wasp stings is to suck hard on the puncture site and spit. Suck and spit. Suck and spit. It’s physics. Sucking reverses the flow of the venom, minimizing the amount of venom that enters the body. Spitting, well, gets rid of the poison you’ve sucked out. To be effective, this must be done asap after the sting.
I’m guessing the sucking and spitting technique might work on scorpion stings, too? (Might require a friend depending on sting location!)😵‍💫

Also, Jeannie mentions Benedryl syrup. Drink dose asap after you’re stung.
In addition, I have found Benedryl CREAM a super useful topical (applied externally) form of the antihistamine, super handy for stings and bites. It works on the site itself. I carry it with me. Not sure if you can buy Benedryl Cream in Mx? Also comes in generic brands.
🏝🏝🔆🏝🏝