What Causes Burning Sensation On Applying Silverdene On Severe Burns?

i have 2nd degree burn to my foot so bad the doc took all the skin off it goes from the middle from the front of leg to the middle of the top of foot ....she gave me silverdene for it problem is every time i put it on it burns feels like my nerves and the hole thing burns so bad i have to scream and take it off done it er 3 times to make sure also the silverdene every time i put it on causes worse swelling after it has been off for a bit it goes down ...is this normal