I've used Aldara previously on my nose, mind you I had to get it in by the container load to cover my schnoz!MrLtL is presently at week 3 of Aldara which is another kind of cream to treat skin cancers. He had one excised from his forehead but the doctor felt the margins were a bit tight. After nearly 3 weeks it's quite red and blistered looking. Certainly doesn't look very attractive. It also seems to be a bit itchy and weeping a little but certainly not the run of possible side affects for your medication listed by marki . He will be pleased when the 6 weeks are up though.
The specialist did say that the chances of a nasty cancer appearing was in the region of 1 in 20,000, if I remember correctly. My immediate thought was that it sounded better than my chances of winning lotto!