In my experience, I have not seen patients develop allergic reactions after receiving Botox Cosmetic or Dysport. Because patients vary in their level of sensitivity, it is my practice, when initiating these treatments, to begin with small doses, titrating upward over a period of time. This approach enables us to monitor a patient’s response thereby reducing the risk of undesirable outcomes. (As with any treatment, it is important to know the credentials and experience of your injector.)
