A diagnosis of late-onset Myasthenia gravis unmasked by topical antibiotics

Myasthenia Gravis (MG) is a disorder of the neuromuscular junction (NMJ) that manifests as fluctuating fatiguable weakness of the muscles. There are many factors that can exacerbate myasthenia symptoms including a variety medications and drugs, systemic illness, and pregnancy. A number of medications have been implicated in exacerbating MG symptoms, including aminoglycosides. We present a case of an elderly female with newly diagnosed MG following the use of tobramycin eye drops for 3 days. There have been limited reports in the literature of topical medications that exacerbate MG symptoms. Clinicians prescribing tobramycin eye drops (or other associated medications) should have a high index of suspicion of MG as early discontinuation and therapy will limit long-term morbidity and mortality in these patients.