THE TREATMENT of hyperfunctional facial lines with botulinum A exotoxin injection is safe, usually effective, and without serious adverse effects. Millions of individual clinical doses have been delivered without major complications. The average lethal dose, at 40 U/kg (eg, 2800 U for a 70-kg person), is orders of magnitude greater than the average dose delivered for glabellar frown lines (15-50 U).1 Indeed, cosmetic use of botulinum A exotoxin has become routine within dermatology. Initiated by pioneering dermatologists, ophthalmologists, and otolaryngologists during the 1980s, and honed by leaders in dermatologic surgery during the past decade,2- 6 techniques for botulinum injection are now commonly taught in residency and postgraduate education programs. Overall safety and efficacy, however, do not imply that bothersome adverse effects seldom occur. There is understandable reluctance to document these, which are usually mild and time limited.7- 12
Yet adherence to a few simple guidelines can reduce the likelihood that the patient will be dissatisfied and the physician embarrassed. Injecting botulinum toxin without subsequent undesired effects is largely a function of knowing where not to inject.
Alam M, Dover JS, Klein AW, Arndt KA. Botulinum A Exotoxin for Hyperfunctional Facial LinesWhere Not to Inject. Arch Dermatol. 2002;138(9):1180-1185. doi:10.1001/archderm.138.9.1180