What Causes Burning Sensation In Healed Skin After A 2nd Degree Burn?

About 2 months ago I burned my thigh doing some soldering. The torch caught my shorts on fire, and ended up with a 2nd degree burn thats about 5"X4" in size. New skin has just about completely filled in the burn, but I am still having a lot of burning. I figured that by the time it filled in that the burning would cease. The wound looks great. Have been using Silvadene 2X a day with sterile dressings.. Could this be some sort of nerve damage, or does it just take longer for the burning to come to an end?