Mimickers of Systemic Lupus Erythematosus: Case Series and Literature Overview

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by a broad and varied clinical presentation. In the absence of definite diagnostic criteria, establishing an SLE diagnosis remains challenging. This case series illustrates that other diseases, such as primary immunodeficiencies and monogenic interferonopathies, can closely mimic SLE, even in the presence of its typical serological markers. Recognizing these disease mimickers is crucial to avoid premature conclusions in clinical evaluation and to ensure the initiation of appropriate therapy. Especially in cases of atypical presentation, unusual disease progression, or resistance to standard therapy, alternative diagnoses should be considered. In this overview, we discuss the diagnostic approach for patients with SLE-like manifestations and provide a comprehensive review of diseases that may mimic SLE.