I got stung by something yesterday while mowing after which my hand and thumb swelled up. Yesterday I took Benadryl and the hand swelling went away completely but my thumb still does any of the following at any given time: remains swollen; itches; hurts if I run any temperature of water across it; tingles; stings.
I took photos, but I have little hope you'd notice the difference.
Here it is (my left hand, thanks, stop making fun of my hands!):