Chapter 23: Botulinum Toxins

INTRODUCTION

Botulinum toxin (BTX), an exotoxin produced by the bacteria Clostridium botulinum, occurs in nature. BTX induces a bilaterally symmetric descending neuroparalytic condition called botulism. The word “botulinum” is derived from the Latin word for sausage, botulus. Botulism was so named during the Napoleonic era in the early 1800s when it was noted to be triggered by the ingestion of spoiled sausages. Later, German physician Justinus Kerner described food-borne botulism and its clinical symptoms during the period between 1817 and 1822. In 1946, Schantz reported isolating BTX type A in its crystalline form, and nearly a quarter of a century later, Alan Scott became the first to harness the effects of BTX for medicinal use in monkey strabismus.¹

The use of C. botulinum A exotoxin, commonly known as botulinum toxin type A (BTX-A), has emerged over the last 20 years as one of the most popular methods of combating cutaneous signs of aging, particularly the dynamic wrinkles of the face. The therapeutic application of this potent neurotoxin has carved a comfortable niche in the cosmetic realm of dermatology practice for practical reasons: Results appear within several days of administration, the procedure itself is short in duration and relatively uncomplicated, and side effects are minimal.

Although medicinal use of BTX by physicians is widespread, professional opinions vary as to the best ways to administer the treatment. For instance, the ideal dilution of the toxin, the number of units to inject, and the longevity of prepared and refrigerated BTX remain debated issues (Box 23-1). The methods described in this chapter are those used most frequently by the authors. The novice injector should try the various methods espoused by experienced specialists to determine which yields the best results in his/her own practice.