I like simple, so I used BC Headache powder, spit and paste .
Mike is correct - I forgot the meat tenderizer , same deal just a paste. Some folks get some relief with Baking Soda paste as well.
Seriously - Benadryl - being a antihistamine, is always smart to have in a first aid kit. Many folks get an allergic reation to bee stings and poison oak/ ivy.
You may want to consult your Doctor, to make sure you don't have some serious allergic reations to Fire Ants and such. As stated above, I've been thru Anaphalactic shock - it ain't fun. I have seen the effects caused from Seafood , bee stings, peanuts, and Asprin on others.
I never had a problem with ASA, granted I rarely take anything anyway. One day I took some Sinus meds with ASA, and WHAM!
AS learned from my Dr., and later in some classes. Anything one puts on their skin or in their body - they can become allergic to. One day the body says " I don't want this" and reacts.
Ladies and make-up, ladies will say " this make-up changed, it breaks me out" . Actually most likely the make-up did not change. Their skin said " I don't want this anymore" and breaks them out.
At least find out how serious a reaction you have, maybe even get a Epi Pen to keep handy - you don't want to get caught out and have more serious reactions.
Check with the local Extension Service and see what they recommend. Also the old guys at Farm & Seed Supply may have some great ideas too about your property.
Good Luck.