Can Someone Be Allergic to Dysport and Not to Botox?

Dysport does contain cow's milk protein and those with an allergy to this substance should not receive Dysport injection.  Botox injection is safe for those patients with cow's milk protein allergy.

Doubt that you have an allergy and think that problem most likely the placement of dysport. Dysport will diffuse more than botox so one must be more careful with injections. Some people seem to be more sensitive than others. I would suggest telling your doctor about this problem so that they can take this into consideration and if all else fails, go back to botox. 

Dysport, like Botox, is a neurotoxin that prevents the release of a chemical that causes muscles to contract.  Thus, it produces a smoothing of wrinkles and lines on the face.  Allergies are very uncommon and almost unheard of with these products - but not impossible. 

The products have some different properties, most notably that the Dysport tends to diffuse further from the site of injection and could have resulted in the eyelid droop.  As for the redness associated with your eye, it is possible that you have symptoms of dry eye and need to have an evaluation by an Ophthalmologist if the symptoms persist.

Best of luck.