Why does Botox cause small whiteheads at sites 2- 4 wk post injection, including at the base of the skull?

Thank you for your question.  Milia and acne are not commonly seen side effects with Botox administration, nor are they listed in the Botox important safety information packet supplied by Allergen.  That said, can a case be made for discrete, localized infections?  Surely.  The injections can cause swelling or edema of the tissues that may prevent clearance of any residual body oil/sebum resulting in a clogged pore, or the trauma of the injections can cause your immune system to ramp up, fighting any small bacteria that may have been introduced with the injection, causing a whitehead to form.  If these possible mechanisms were to take place, however, I would anticipate that you would get the whiteheads in the first few days after injection, and not 2-4 weeks later.  So as far as timing, I am not sure why they are developing.  Hope this helps.

Thank you for submitting your question.  Botox rarely cause mila or small whiteheads from forming.  Make sure your physician uses alcohol based cleanser prior to injection. Good Luck

Botox is actually used in some cases to treat acne so I'm unsure if what you are describing is actually acne, or possibly milia. Milia can form in areas, usually thinner skinned areas, that are prone to slight injury or rubbing. "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."