Shrinking lung syndrome in primary Sjögren's syndrome: a case-based review.

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease that affects exocrine glands, mainly the salivary and lacrimal glands, leading to the development of sicca symptoms. Patients with pSS may also present with extraglandular manifestations, including lung involvement, estimated to occur in 9-24% of cases. Shrinking lung syndrome (SLS) is an uncommon respiratory complication primarily associated with systemic lupus erythematosus, with a prevalence of approximately 1% in these patients. It typically manifests as dyspnea, pleuritic chest pain, lung volume reduction, and a restrictive pattern on respiratory function tests. Cases reporting SLS with other connective tissue diseases, including pSS, are even rarer. Herein, we describe a case of a 57-year-old woman with a 10-year history of pSS who presented with dyspnea and pleuritic chest pain. After evaluation, the patient was diagnosed with SLS based on clinical, radiologic, laboratorial, and electrophysiologic characteristics. In addition, we identified and analyzed previously published cases of SLS in pSS. Treatment includes corticosteroids, immunosuppressants, and respiratory muscle training. This study highlights the importance of considering SLS in the differential diagnosis of patients with pSS and respiratory symptoms.