Could Botox cause a lump like blister?

It is difficult to answer this without a picture. What do you describe as smoker's lines? Do you mean those in the lip? It is highly unlikely for botox to have caused this effect. I suspect that it is something unrelated. If it doesn't go, then best go back to your doctor to have a quick look.

From your  description it appears you may have a "cold sore" which is caused by a virus. It does not matter too much wether you have had previous breakout or not; it is considered that every adult harbors this virus and under some conditions it may express itself. At the point where you have developed a blister the treatment may not be very effective but you should contact your injector for further advice. If that's what it is you may need to take  prophylactic doses before the next injection.Good luck!