A case of SARS-CoV-2 infection during the course of SLE - difficulty in differentiating neuropsychiatric SLE from multisystem inflammatory syndrome in adults.

The global COVID-19 pandemic has also brought attention to multisystem inflammatory syndrome in adults (MIS-A), a post-COVID-19 complication. Here, we present a case of MIS-A caused by COVID-19 after the patient had systemic lupus erythematosus (SLE). A woman in her 30s developed SLE. Two years later, she became aware of arthralgia and was febrile. On admission 2 weeks later, she had three episodes of generalised clonic seizure and a SARS-CoV-2 Polymerase Chain Reaction (PCR) test was positive. Blood tests showed an elevated C-reactive protein (CRP) level. Cerebrospinal fluid was negative for bacterial culture but showed elevated interleukin 6. Magnetic resonance imaging (MRI) Fluid Attenuated Inversion Recovery (FLAIR) showed high signal in the brain surface from the right frontal to the temporal lobes. Antimicrobial agents, methylprednisolone pulse therapy, and anticonvulsants were started on admission day. The seizures resolved, but the fever persisted and the CRP level increased again. The patient was negative for other conditions that might explain the severely elevated CRP but met the Centers for Disease Control and Prevention 2020 diagnostic criteria for MIS-A. After a second methylprednisolone pulse and 3-day intravenous immunoglobulin therapy, her fever resolved, the CRP level decreased, and the MRI abnormalities and cerebrospinal fluid findings improved. Differential diagnosis is important when central nervous system symptoms are present in patients with SLE. If patients develop neuropsychiatric manifestation after SARS-CoV-2 infection, the possibility of MIS-A should be considered even in SLE patients.