After a couple of months of continuous use of Tolak (fluorouracil), I began having headaches. This occurred after I began treating both forearms at the same time. I've read that the area of skin covered by fluorouracil should be no larger than about 75 square inches. The area of my forearms is about 100 square inches, so I assume that perhaps this is what caused the headaches. Anyone else experienced anything similar to this?