Extensive myofascial necrosis: a delayed complication of botulinum toxin therapy

Botulinum toxin is now an important therapeutic agent in various clinical specialties. Although a lot is known about its short-term effects, little is known about the long-term effects or delayed complications. Most of the therapeutic effects appear within a week and last for 10-12 weeks. In most cases, the side effects are mild and often self-limiting and tend to occur within the first week. Myofascial necrosis and delayed onset of side effects are rarely reported and present a new challenge for a drug that has been proclaimed as an anti-ageing drug by the lay press and is widely used outside the licensed indications.