Wellbutrin and prednisone

After taking wellbutrin xl 150 mg. for 2 weeks, my 13 year old son broke out in large red hives that over the course of the last few days have covered his body from head to toe. He has joint pain and is itching like crazy. Doctor prescribed prednisone and he's also taking benadryl. Doctor thought the hives could be a virus but doesn't seem so given all of these posts. He's stopped taking the wellbutrin today. The wellbutrin was so helpful for his depression but the hives are horrible. Any idea how long the hives will last?

I AM SO RELIEVED TO HEAR ALL OF THIS. MY LIFE HAS BEEN TURNED UPSIDE DOWN AND SHAKEN UP SO BAD FROM THESE HORRIBLE HIVES. TOOK WELLBUTRIN XL 150MG FOR 2 WEEKS AND THEN WENT UP TO 300MG ABOUT 1 WEEK LATER NOW THIS! I AM SO MISERABLE. MY ARMS HURT, MY HEAD FEELS LIKE I HAVE BUGS ALL OVER IT, AND THE HIVES ARE EVERYWHERE. THINGS THAT ARE HELPING ME COPE- AVEENO OATMEAL BATH IN LUKE WARM WATER (NOT HOT!) BENADRYL CAPSULES, AND BENADRYL CREME. I HAVE BEEN TO THE DOCTOR TWICE AND WAS AT THE ER LAST NIGHT DUE TO TIGHT CHEST AND THROAT. WAS TOLD I HAD HIVES INSIDE ON MY ASSOPHAGIS (spelling? lol) ALSO. SO SCARY. I AM PRAYING THEY GO AWAY SOON.