Abstract
Psoriatic arthritis (PsA) is a chronic inflammatory condition affecting approximately 30% of individuals with psoriasis, while myasthenia gravis (MG) is an autoimmune neuromuscular disorder caused by antibodies targeting acetylcholine receptors, leading to progressive muscle weakness. Although autoimmune diseases often coexist, concurrent presentation of PsA and MG is exceedingly rare and poorly documented. We describe a 66-year-old male with a longstanding history of psoriasis and PsA, previously well controlled on methotrexate, who developed seropositive generalized MG after discontinuation of his methotrexate therapy. When methotrexate was reintroduced for PsA management, he demonstrated marked and sustained clinical improvement in both his psoriatic disease and neuromuscular symptoms. This case highlights the challenges of managing coexisting autoimmune conditions and emphasizes the need for further investigation and clearer guidance for such complex clinical scenarios.
Keywords
Methotrexate, Psoriatic arthritis, Myasthenia gravis