Development of botulinum toxin therapy.

Justinius Kerner collected data on 230 cases of botulism in the 1820s, suggested the therapeutic use of toxin, and gave a remarkably complete and accurate description of clinical botulism: its symptoms, time course, and the physical findings that the tear fluid disappears, the skin is dry, the eye, gut, and somatic muscles are paralyzed, and mucus and saliva secretion is suppressed. These effects are the clinical targets of botulinum therapy today. Inspired by Drachman's use of toxin to safely paralyze the hind limb in chicks, we worked out the procedures for its safe medical application and licensure from 1972 to 1989, applying it first to correct strabismus, blepharospasm, leg muscle spasm, and torticollis. This list is now extended by others to well over 100 uses. For many years, blepharospasm patients returning for injection around the eyes and upper face would mention as a joke that they were "back to get the wrinkles out." Working in aesthetic dermatology and ophthalmology, Alistair and Jean Carruthers could envision the intentional cosmetic application of botulinum toxin, probably its greatest single use today.