Is there any evidence that MS patients have antibodies that reject Botox & other cosmetic treatments?

While there is no evidence of MS patients having antibodies that reject Botox, MS is a disease that affects the nerves and muscles, so it is best to have any Botox treatment cleared with your neurologist before having it as a cosmetic treatment. Botox affects the muscles in the face so it’s better to be safe. Other types of cosmetic procedures such as dermal fillers or laser resurfacing should be fine, as these treatments do not affect the nerves or muscles. 

When Botox originally came out there was some theoretical concern that it might have adverse effects in Multiple sclerosis patients.  In the current day, multiple sclerosis patients are safely receiving Botox treatments for spasticty issues, in much higher doses than we use for cosmetic treatments. No, to the best of my knowledge, there is no evidence that MS patients have antibodies that cause them to reject Botox or other cosmetic treatments.  

Having MS means that your are subject to muscle weakness. Getting Botox might make things worse with MS so I don't give it to any MS patients. Filler would be fine in MS patients.