Primary Sjogren's syndrome presenting as ptosis and eyelid swelling: A case report.

Key Clinical Message: This unique case report of primary Sjogren's syndrome (pSS) shows bilateral ptosis and significant periorbital edema, compromising vision. To avoid misleading diagnosis, antibody tests must be evaluated and interpreted in the context of clinical findings. Abstract: Primary Sjögren's syndrome is an idiopathic, autoimmune disorder involving the lacrimal and salivary glands characterized by both localized and systemic manifestations including xerostomia and keratoconjunctivitis sicca. Myasthenia Gravis (MG) is also an autoimmune disorder characterized by the development of auto-antibodies against nicotinic acetylcholine receptors that causes decreased muscle response to stimulation. It usually presents with ptosis and generalized body weakness. Ophthalmological involvement is common in both disorders but ptosis is very rarely seen in pSS. We report the case of a 27-year-old woman presenting to our clinic with the complaint of ptosis and eyelid swelling. She also had a positive anti-acetylcholine receptor antibody test and her initial presentation mimicked Myasthenia Gravis. Her autoimmune workup revealed a positive titer of Anti Ro SSA antibodies. Myasthenia Gravis was ruled out on electrodiagnostic studies which showed no decremental response, and pSS was confirmed on lip biopsy. Our case highlights that it is important to interpret the antibody test results in the context of clinical findings as we can have spurious results in autoimmune diseases. Autoimmune conditions can have varying presenting complaints hence, clinical judgment should always overrule diagnostic investigations and should thus guide patient management.