it is a reaction, i would suspect, to the ph in whatever got you or touched you. at this point, not sure you can do much but wait it out. but for the next one try wetting baking soda in some purified water and glop it on (youll know in a few min if it helps) when you first notice. the off ph is like "burning" your arm, you didnt neutralize it so it made it a good size burn.
that is all farm-lore from Mamie, my grandmother. but it is pretty simple and shouldnt hurt you for the effort if it doesnt work, but if it works, then good. i wish i had written things down, but she used things like tobacco, baking soda and vinegar for things like medicine, pesticide and cleaning.
some people are more sensitive to ph for sure, sort of like the plants!