I got injected with Dysport 2 weeks ago and 5 days ago. I started to have major pimples on my forehead, is it caused by Dysport?

Pimples and breakouts are unlikely related to Dysport injections. There are some rare, and potentially serious, side effects such as viral outbreaks that should be ruled out. I would recommend you follow up with your plastic surgeon for an evaluation if you haven't done so already. Post an update when you get a chance. Good luck!Dr. Harmych

Dysport is a neurotoxin used to stop the muscles that it is injected into from moving. I also has the ability to decrease the amount of sweat and sebum released in the areas surrounding the injection sites. Acne is caused by the skin follicles getting occluded and oil and bacteria causing a pustule in the follicle. If the bumps on your head persist, see your injecting physician for further evaluation.

The sebaceous glands secrete sebum, the major cause of acne. Release of sebum is inhibited with Dysport.  I have many patients where they know their Dysport treatment is needed because their acne flairs. I'd look at some other cause. 

Dysport and Botox can actually be effective treatments FOR acne, because they inhibit sebum release from the sebaceous glands there. So unless, your injector used a topical numbing cream prior to treatment that you are having some kind of reaction to, then the acne is not from the Dysport...."This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."