Shrinking lung syndrome in systemic lupus erythematosus: a systematic review

Introduction Shrinking Lung Syndrome (SLS) is a rare pulmonary complication of Systemic Lupus Erythematosus (SLE) and other connective tissue diseases. SLS is characterised by dyspnoea, restrictive lung pattern and elevated hemidiaphragms. The pathophysiology of SLS is unclear and there are currently no defined diagnostic criteria or standardised treatment guidelines. Increasing clinical awareness is essential to reduce diagnostic delay and improve patient outcomes. Methods A literature search was conducted on the MEDLINE and Embase databases from January 1946 to 29th December 2025 to identify studies evaluating shrinking lung syndrome in patients with systemic lupus erythematosus. Data extracted included age, sex, presenting symptoms, imaging, PFTs, phrenic nerve or diaphragm studies, immunologic profile, treatment and follow-up outcomes. Results A total of 34 studies were included, all of which consisted of case reports, case series and one cross-sectional study. We pooled 120 patients, 86% of which were females and ages ranged from 12 to 67 years, including paediatric cases. Dyspnoea was present in 98% of patients. Elevated hemidiaphragms were seen on imaging in 78% of patients. Pulmonary Function Tests (PFTs) showed a restrictive ventilatory pattern in 91% of patients. Corticosteroids were the first-line treatment in 93% of patients. Symptomatic improvement was seen in 77% of patients. Reported follow-up periods ranged from 3 weeks to 20 years. Discussion Early recognition of SLS and tailored immunosuppressive therapy can achieve good outcomes for patients.