Hi i do care for your concern.
The bee sting usually cause hypersensitive reactions, and cause swelling of lips.
In your case the sting was 8 days ago.
I would advise to consult your physician and get thoroughly examined for any insect particles left over in the stung regions.
In most cases tablet cetrizine would help to control itching.
And due to inflammation the pain may be present, hope the condition recovers soon.
Hope i have answered your question, If you have more feel free to ask.
Thank you.

This sounds like urticaria with angioedema (hives). This could be caused by a virus, which may also cause joint pain. Is there any history of a sore throat in the past couple weeks? Any recent medications? Has he ever had a reaction like this before? Is he having any trouble breathing, or have any abdominal pain? Any travel out of the country? Any foods out of the ordinary? Any exposure to extreme hot or cold? Did he have any immediate reaction to the bee stings? Otherwise he is in good health? Only if the reaction started soon after the bee stings would you think about an anaphylactic (allergic) reaction, but if he was having fevers, the welts hurt, or if they lasted longer than 24 hours, he may be having a different kind of reaction to the bee stings, and I would recommend getting his blood checked. Normally hives go away after 24 hours. You can give an antihistamine to him (like cetirizine) for the itching.