How are neutralisations used to treat wasp and bee stings?

With wasp and bee stings the venom has been injected under the surface of the skin. There is nothing you can put on the surface of the skin that will neutralise the venom. All you can do is treat the symptoms: a painkiller to ease any pain; an antihistamine to counter any swelling; and something like calomine lotion to stop any residual itching.