Can I Inject Botox if I'm Allergic to Penicillin and Erythromicyn?

There should be no cross reactivity with Botox and the two antibiotics you mentioned, penicillin and erythromycin.  In fact, I have never seen an adverse allergic reaction to Botox, Dysport or Xeomin in any of my clients over the years.  

Luckily the ingredients in Botox are not related to any of the antibiotics you listed.

Allergies to Botox are also very rare.

However if you are a sensitive individual i would ask your dermatology provider to do a test spot-- to see if you have any unwanted reactions.