Shrinking Lung Syndrome in a Systemic Lupus Erythematous Patient Improved by Rituximab: A Case Report With Literature Review

Abstract

Shrinking lung syndrome (SLS) is a rare complication of autoimmune and connective tissue diseases like systemic lupus erythematosus (SLE). A 35-year-old female patient, diagnosed with SLE, came to the hospital complaining of severe dyspnea and pleuritic pain for several months that was worsening on exertion. Imaging (X-ray and CT scan) of the chest at the time of presentation showed bilateral basal atelectasis with elevated diaphragm. Pulmonary function test (PFT) showed restrictive findings including forced expiratory volume in the first second (FEV1) of 37%, total lung capacity of 40%, and vital capacity of 32% predicted with a restrictive pattern on flow volume loop confirming the diagnosis of SLS. The treatment focused on methotrexate and rituximab. Patients with a known history of SLE who start respiratory symptoms like cough and dyspnea should be ruled out of SLS at the earliest as it can be deadly in the later stages.