How Much Dysport is Enough for Just Crows Feet?

The amount of Dysport used to treat an area can vary by individual, but I would say I more commonly use around 60 units total to treat just the crow's feet area.  I would consider 120 units a large dose to treat only the crow's feet.    

Your pictures indicate you may be referring to the glabella instead of the Crow's feet area?  The muscles creating these vertical wrinkles can be very strong, and can require 50-80 units of Dysport to soften.  With this dosage you should not see much muscle movement, although with deep wrinkles you may still see the furrows at rest.  

The first point I would make is that I have never seen or heard about a true allergic reaction to Botox.  I would encourage that you explore this further to determine whether a true allergic reaction was present:  global skin rash, airway symptoms etc.  Regarding Dysport, the average dosing I recommend in the crows feet is 50 units or 25 units per side.  A higher dose may be used in some patients.  120 units of Dysport to the crows feet alone is very high.

The standard dose for Dysport for crows feet in my practice is 25-30 units per eye for a total of 50-60 units. As other docs have noted I have not seen a true allergic reaction to Botox either and I agree you should investigate those symptoms to see if they were from something else. I am happy you have found an alternative to the Botox, but 120 units is a large amount around the eyes only.