I've never used meat tenderizer on bee stings, but this is a common
field first aid technique for various bites.  Papain is an enzyme,
and enzymes digest molecules.  The various chemicals injected by
mosquitos, sting rays and bees cause an immune response (itch, pain
swelling) which can be lessened if the offending molecule is digested
or in some other way neutralized.  Ammonia (a strong base) can have
the same affect by altering the pH of the injected venom; it certainly
makes mosquito bites itch less.
 
Amazing, isn't it.
Carol K. Malcolm
Central Texas Beekeeper
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