Background
Botulinum toxin is the product of Clostridium botulinum. C botulinum bacteria and their spores are ubiquitous. The bacteria are found in soil and marine sediments; the spores can be detected on fruits and vegetables and in seafood. The growing bacteria produce the neurotoxin botulinum toxin, which is often referred to as the most poisonous substance known to mankind. The neurotoxin inhibits the release of acetylcholine and results in the flaccid paralysis of the affected muscles.
Seven serologically distinct types of botulinum toxin exist: A, B, C1, D, E, F, and G. Botulinum toxin type A (BOTOX®; Allergan) was the first commercially available type in the United States.
The different types of botulinum toxin have different molecular sizes, degrees of activation, and mechanisms of action. Various commercial preparations have different characteristics regarding their clinical performance. Significant research is underway to study the molecular causes of these differences.
The available types of botulinum toxin type A are named onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and prabotulinumtoxinA. Botulinum toxin type B is named RimabotulinumtoxinB. OnabotulinumtoxinA is marketed as BOTOX®/BOTOX® Cosmetic, abobotulinumtoxinA as Dysport®, incobotulinumtoxinA as Xeomin®, prabotulinumtoxinA as Jeuveau®, and rimabotulinumtoxinB is marketed as Myobloc®.
This article focuses on the dermatologic applications of botulinum toxin in general. The reader should note that the dermatologic use of botulinum toxin requires an in-depth knowledge of the anatomy and function of the areas treated (eg, in the case of the face, facial muscles, and their relations with the orbit). From the cosmetic point of view, an understanding of the complex functions of the muscles to be injected is especially important.
Botulinum toxin has beneficial effects only on wrinkles caused by muscular contractions. Botulinum toxin is not an appropriate treatment for wrinkles caused by solar exposure or other degenerative processes of the dermal tissues. This article provides only an overview of the technique and of several clinically relevant issues and does not replace hands-on training and experience.
For patient education resources, see the patient education article BOTOX® Injections.
Several Medscape articles address botulinum toxin–related procedures, as follows:
Dystonia Treatment using Botulinum Toxin
Botulinum Toxin in Pain Management