Complications with the use of botulinum toxin type A for cosmetic applications and hyperhidrosis.

In dermatology, botulinum toxin is now most often used to reduce dynamic facial creases and treat primary focal hyperhidrosis. The exemplary safety record of this medication is such that after nearly 2 decades, it is not known to have any long-term adverse events. Transient adverse events, such as mild injection pain, are typically minor and spontaneously remitting. Headache, nausea and flu-like symptoms, lid and brow ptosis after upper face injection, lower face asymmetry after perioral injection, and fine motor impairment after palmar injection are uncommon to rare. Understanding of anatomic landmarks and site-specific precautions can further mitigate the incidence of unwanted effects. Patients who do experience uncommon, transient effects can be reassured that these are not dangerous and will resolve completely without intervention.