Bee stings immune response

a friend of mine drove into a swarm of bees - left about 15 on the windshield - and one sting in his left hand (out the window of course). He immediately got the stinger out w/out rupturing the sac. According to him, he’s never been stung before.
So he had the usual redness, some itchiness - but ALOT of swelling - lost the knuckles on his hand, very painful - for several days.
then after symptoms subsided, about 1 week post-sting, his hand swells again and the itchiness returns.
So - what’s going on? I’m thinking that the 2nd wave sounds like a humoral immune response, since the timing is about right for an Ab response - but what is it reacting too? Surely the bee venom is gone by now ?

I think you're right, he's having some sort of specific immune response. Could be to residual bee venom, I suppose. We may never know. Some people get these big local responses to bee and wasp stings, BTW. A big local response does not increase the risk of subsequent anaphylactic reactions to stings. But a delayed response suggests he has become sensitized to bee venom. I'd warn him to be cautious if he gets stung again.

thanks Betsy - I'll pass along the warning -