Stung by a bee yesterday at approximately 2:30 PM. At the time, minor swelling and some pain. I went to a First Aid tent at the outdoor concert and was given some serum-like treatment and sent on my way. The next morning, my whole forearm turned red, hot, swollen, sensitive to the touch yet numb, and a bit itchy. I have been stung several times as a child, but this is the first time I had an adverse reaction that I can recall. I planned on taking Benadryl to treat it. How long should I wait until I should seek some medical advice?