Botox

• Botox is the brand name for botulism toxin, a bacterium known to cause food poisoning. While poisoning does not result from Botox cosmetic injections, the toxin acts as a muscle relaxer that reduces the appearance of wrinkles.
  
  

Swelling

• The Mayo Clinic warns that swelling, along with redness and bruising at the injection site, is a possible side effect of injection with Botox. Swelling can be caused by a number of factors, including medication reactions or reactions to the method of injection. The swelling should subside within a two to three days of injection, according to the Mayo Clinic.
  
  

Complications

• Severe swelling, along with hives, tightness in the chest, difficulty breathing, severe rash or peeling of the skin and eye pain are among uncommon but serious side effects associated with Botox injection, according to Mayo. You should consult a doctor right away if you experience any of these symptoms.