My 5 yr old son received his 5yr old booster which was his Di[htheria, tetanus, pertussis & polio. A day after the shot his arm swelled up and was very red and hot. I took him to the walk-in and the Dr. said it was a reation to the shot and that was about it. However, about 8 weeks went by and at bedtime I noticed a large quarter sized hive in the area where he received his needle. I gave him some benadryla nd it went away. Aweek later he has been having 1 or 2 hives in the same area no where else on his body. I just not sure what to do or if its a reaction from his needle?