Benadryl for sure, but watch it closely. 2 of my boys have had weird reactions to bee stings, one ended up in the ER and the other had a couple trips to the Ped for it. It started swelling like that and on day 3 he couldn't walk and it started blistering, turning purple and got a streak. He was on abx and steroids for a week.
The last one said his throat was funny and he couldn't breathe right and we had to rush him to the ER, got steroids, Benadryl and Pepcid. He has an epi-pen now and we keep Benadryl with us and at school. Also had a week of steroids for his too.
I would also just consider them allergic to bee stings. It may have been this way this time, but next time could be completely different and fatal.
Kristi, Mommy to Josh & Nick (identical twins 6-97) Nathen (3-02), Joey (2-04), Jacob (11-05) & Aaron (12-11) I sell Tupperware!
"A person's a person, no matter how small..." Dr Seuss