Oculopharyngeal muscular dystrophy, myasthenia gravis, systemic lupus erythematosus: overlap and interactions

Ptosis and proximal weakness may develop in multiple diseases including oculopharyngeal muscular dystrophy (OPMD) and myasthenia gravis (MG). These two entities can be challenging to differentiate since they may have important clinical and neurophysiological overlap. Systemic lupus erythematosus (SLE), a common autoimmune disease, has been described in association with MG.We present a woman in her 60s with fluctuating bilateral ptosis and proximal muscle weakness. Single fibre electromyography showed increased jitter. Her brother has genetically proven OPMD. The investigation revealed a positive genetic test for OPMD and positive antibodies for acetylcholine receptor. Additionally, she has SLE, treated with hydroxychloroquine for more than 30 years.This case highlights the importance of a thoughtful anamnesis with personal and familial history and raises awareness for the rare coexistence of three pathologies with some common clinical characteristics but different treatments and management.