Does Botox Causes Severe Itching and Rash?

To develop vague symptoms a month after Botox is doubtful that Botox is the cause. You should see a neurologist to make sure there is no unrelated underlying neurological condition. Although, very rare, some conditions which may have minimal symptoms could go undiagnosed until exacerbated by Botox such as myasthenia gravis. It is doubtful that this is the cause but see a neurologist to be thorough.

The Botox can rarely cause ptosis, the medical term for eyelid drooping but it would occur in less than 2 weeks, not one month later. The itching and swelling as well as the severe poking pain one month later is likely not related to the Botox and requires more investigation to determine the casue and try a remedy. I doubt the antihistamines suggested would help.

It is very unusual to have any side effects to Botox one month later.  Eyelid droop can happen and is one of the known side effects but face swelling and itching are not.  Very rarely, one can be allergic to albumin which is a protein found in the product and this can potentially produce some of the symptoms you are experiencing.  You should definitely follow-up with your doctor.