Had Surgery. On Benedryl. Had Swollen, Red, Itchy Feet, Hands, Face. Allergic Reaction To Anesthesia?

I recently woke up from surgery 13 and 1/2 hours later than anticipated because I had been kept asleep with the use of Benedryl to keep me from suffering from an onset of swollen, red, itchy feet, hands and face. It took about 5 days for the swelling to go down on its own without further medication. I am concerned it could have been an allergic reaction to anesthesia and want to know what it was to avoid this happening to me again the next time I may need anesthesia. On repeated inquiries of the hospital and 2 doctors, no one can find any record on my chart of this happening. What should I do?