The most likely triggers for acute urticaria are
allergies to pets, horses, latex
and foods, such as shellfish
and nuts,bee or wasp stings,allergies to medicines,Viral infections, such as glandular fever and herpes, dental and sinus infections, fungal infections, blood transfusions and vaccines.
In your case the bee sting can be responsible for these hives. The mainstay of treatment of hives is antihistamine which may be necessary for prolonged periods (in excess of 6 weeks).