Is there a risk of getting botulism or can the toxin spread from having Dysport 20 units in forehead?

Please understand that the list of risks on most medication labels is exhaustive for the sake of risk management.  I would place your risk of clinical botulism from 20 u of Dysport at a click north of zero. 

No, you will not get botulism from your Dysport injections and it won't spread after injection. Keep in mind, you may have some swelling after your procedure, which is typical and will resolve in 1-2 weeks. Best, Dr. Emer