The use of
botulinum toxin A in cosmetic dermatology has increased in popularity due to the efficacy and relative safety of the treatment.
Botulinum toxin A is one of eight
exotoxins produced by Clostridium botulinum, a Gram-positive, spore-forming anaerobe. Flaccid
paralysis results from the
denervation of muscle fibers at the neuromuscular junction after
botulinum toxin A administration. While treating
blepharospasm, the Carruthers incidentally found that
botulinum toxin A improved glabellar frown lines. Dynamic rhytides occur in areas of dynamic motion. These types of lines may be improved with
botulinum toxin A. There are two types of
botulinum toxin A commercially available (
BOTOX and
Dysport); only
BOTOX is currently available in the US. The efficacy and tolerability of
BOTOX was best demonstrated with a multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of
botulinum toxin type A in the treatment of glabellar lines in 264 patients. There was a significantly greater reduction in glabellar line severity with
BOTOX. The effect was maintained for the duration of the study (120 days). There was low occurrence (5.4%) of mostly mild
blepharoptosis in the
BOTOX group. In another prospective study, it was found that about 1% of
BOTOX patients reported severe
headache.
Botulinum toxin A can provide an alternative treatment of palmar and axillary
hyperhidrosis when options such as topical agents (
aluminum chloride) and iontophoresis have failed.