Myasthenia gravis exacerbation with low dose ocular botulinum toxin for epiphoria.

We present a man with clinically stable systemic myasthenia gravis (MG) which flared with a low dose of peripherally injected botulinum toxin type A (BTX-A). Botulinum toxin drugs generally have an excellent safety profile, however, they are contentious in patients with neuromuscular disorders. Despite this, there remain limited reports on the systemic effects of botulinum therapy in patients with MG. This man is one of less than 10 reported patients worldwide in whom MG was exacerbated by a peripheral BTX-A injection. This is an important reminder to Australian clinicians of the potential risks of this common place medication in patients with neuromuscular disorders, even those with stable disease.